Following the unexpected stock shortage of the Rivemove since May 2022, there is currently no alternative product on the market. We has received numerous inquiries and recognizes the urgency felt by parents. It’s important to clarify that the WIDFIX Extender Series is a distinct product from the Rivemove. Our developers have strengthened the structure and materials of the extenders, addressing the limitations of the Rivemove and resolving concerns raised by parents. This guarantees a smoother experience for parents, coupled with improved compatibility with a range of car models and car seats.

The WIDFIX and the Rivekids Rivemove

Safety Features

The WIDFIX ISOFIX extender is available in two versions: WIDFIX and WIDFIX PLUS.

WIDFIX: Similar to the Rivemove, this extender is designed for forward-facing ISOFIX car seats with three-point belt installation, specifically for Groups II to III (children weighing 15-36kg / 33.1-79.4lbs). It has successfully passed crash tests. Parents seeking specifications similar to the Rivemove can refer to the WIDFIX.

WIDFIX Plus: In response to the growing demand for newborn car seats, the PERO design team has developed the WIDFIX PLUS, providing enhanced stability, safety, adaptability, and large adjustments. Compared to the WIDFIX and the Rivemove, the WIDFIX PLUS features a higher-strength structure, making it the only ISOFIX extender on the market suitable for all types of car seats (Groups 0 to III).

★  The WIDFIX has successfully passed crash tests with KIDSPERO car seats.

PERO consistently prioritizes car seat safety. The WIDFIX, our latest development, underwent rigorous crash test in accordance to car seat regulations. Every possibility is taken into consideration to ensure optimal safety and that no components eject or falter under 1000 kilograms of force

However, since the WIDFIX is not categorized as a car seat, it is not subjected to specific regulatory tests. We have successfully passed the crash test with the PERO car seat, but laboratories are not able to issue any relevant certificate or reports indicating completion. The crash test data is stored on the laboratory computer and is accessible only to internal personnel due to confidentiality agreements. This limitation applies to both Taiwanese and European laboratories. The WIDFIX is not the only accessory product unable to obtain car seat certificates; similarly, all automotive accessories (such as the Rivemove, seatbelt extenders, etc.) cannot receive laboratory-issued certificates.

WIDFIX and Rivekids Rivemove


MaterialsTaiwan high-quality steelGalvanized ironTaiwan high-quality steel
Length of extension per side0-7cm5cm or 7cm 0-8.5cm
AdjustmentLimitless adjustmentTwo-section adjustmentLimitless adjustment
FixedStainless steel screwMetal clipStainless steel screw
Anti-crash★★★★☆★★★☆☆ ★★★★★
TestEN Crash testEN Crash testEN Crash test
Carseat weight GroupsGII-GIIIGII-GIIIG0-GIII
Carseats3-point seatbelt
Front-facing carseat
3-point seatbelt
Front-facing carseat
360 rotational carseat
3-point seatbelt & harness
Front & rear-facing carseat
WIDFIX and Rivekids Rivemove
WIDFIX and Rivekids Rivemove

Exterior Distinctions

Material Composition

WIDFIX prioritizes meticulous material selection for its products. The outer base of the extender is crafted from high-quality steel in accordance with Taiwanese CNS standard SS series. The screws and anchors on the extender utilize stainless steel, renowned for its exceptional corrosion resistance and rust-proof characteristics. This resistance to corrosion ensures the extender remains unaffected against oxidation or corrosion, safeguarding its structural integrity. The WIDFIX subjects its products to rigorous laboratory saltwater tests, showcasing outstanding corrosion resistance even with prolonged usage. This exceptional durability is a fundamental element in providing maximum safety assurance for children.

WIDFIX and Rivekids Rivemove

The Material of the Coat

The environmental-friendly matte-black coating is smooth and durable preventing potential damage. If the stainless steel was exposed, it would oxidate and begin to deteriorate.

WIDFIX and Rivekids Rivemove

ISOFIX Lower Anchors

The tolerance of the Rivemove is relatively larger. Parents using brands such as MAXI-COSI have reported that the lower anchors are thicker and the ISOFIX connectors get stuck on the anchors. This typically causes damage to the anchors and the connectors when attempting  to detach.

The PERO development team has an extensive background in the development of carseats. The WIDFIX is manufactured with 100% accordance with carseat specifications. The WIDIFX universally attaches to any carseat with ISOFIX connectors.

WIDFIX and Rivekids Rivemove

Reduced Gap

The WIDFIX creates a smaller gap between the car seat and the vehicle seat compared to traditional car seats. This causes the car seat to have a reduction in shaking from the car. 

Additionally, we designed an exclusive WIDFIX Protection Cushion to help the child’s rides be more comfortable. Our products are always non-toxic, odorless, safe and comfortable.

WIDFIX and Rivekids Rivemove

WIDFIX Adjustment

WIDFIX has the ability to always move to the required legnth with our positioning point locks with screws. Our design makes a more stable and safe adjustments that effectly reduce any chance of shrapnel from the device expelling compared to Rivemove’s design.

The Rivemove’s spring design has a metal ball that goes into slots by pushing down on the button and moving the device. This mechanism could cause potenial pinching or damage to the fingernail.

The WIDFIX displacement mechanism has a screw locking design that has better stability and limitless adjustment for optimal length for each vehicle. There is no need to worry about not having the correct fit with the WIDFIX.

WIDFIX and Rivekids Rivemove

Purchasing the WIDFIX

Which WIDFIX should I choose?

Depending on the type of the car seat, the selection of WIDFIX will be different. Parents should choose the applicable device based on the following points: 

  • WIDFIX:GII-GIII isofix car seats and isofix boosters
  • WIDFIX PLUS:G0-GIII isofix car seats and isofix infant carriers (for all types of isofix car seats)
  • WIDFIX: 3-point belt
  • WIDFIX PLUS: 3-point belt and harness

This is the most intuitive way to choose a WIDFIX. Once the child uses a harness, it is recommended to choose WIDFIX PLUS.

Where can I buy WIDFIX?

The WIDFIX ISOFIX extender is developed by PERO. Interested parents can follow PERO Facebook to be notified of the latest news, or click on the desired product below to purchase from the PERO offical website.



WIDFIX ISOFIX extenders are divided into two specifications, one is WIDFIX and the other is WIDFIX PLUS. The main differences are as follows:

  1. WIDFIX ISOFIX extender metal thickness is thicker
    The metal of the WIDFIX ISOFIX extender has ED coating, and part of it is stainless steel, so the entire extension will not rust.
  2. WIDFIX ISOFIX extender has better impact resistance.
  3. WIDFIX ISOFIX extender displacement has no limit on the number of segments.
  4. WIDFIX ISOFIX extenders are less wobbly.
  5. Rivemove is fixed with spring clips and WIDFIX ISOFIX extender lock screws to prevent it from popping open in the event of impact.

WIDFIX and Rivemove are different products. WIDFIX ISOFIX extender is developed locally in Taiwan and provides prompt customer service. Both WIDFIX and Rivemove were sent to the EU laboratory for crash tests, but the laboratory does not issue any certificates to car seat accessories.


  • Material thickness: 2mm
  • Length of extension per side: 0-70mm
  • Anti-crash: ★★★★☆
  • Applicable car seat: GII-GIII car seat


  • Material thickness: 2.5mm
  • Length of extension per side: 0-85mm
  • Anti-crash:★★★★★
  • Applicable car seat: G0-GIII car seat

In the forward and back facing car seats that have a harness / five-point belt, the lower anchors must withstand a high amount of impact. The development team strengthened the design and created the WIDFIX PLUS for car seats with a harness / five-point belt.

WIDFIX is for forward facing car seats with three-point belt has the energy transferred through the lower anchors and the safety belt, so the strength needed from the lower anchors is decreased.

The WIDFIX ISOFIX extender has wider car adaptability than the Rivemove. The displacement mechanism of the WIDFIX ISOFIX extender is not limited by the number of segments. It has better displacement adjustment, and can be adjusted according to the distance between the car seat and the door.

In addition, the WIDFIX ISOFIX extender has rounded edges and bevels to prevent damages to the vehicle. The WIDFIX allows for unlimited adjustments, being able to maximize the space in the back seat compared to segment based adjustments that may not have the optimal length for your vehicle. Compared to Rivemove that only provided 2 adjustments that maybe too short or too long for your vehicle seat.

PERO developed a custom fitting auxiliary cushion for the WIDFIX ISOFIX extender – the WIDFIX Comfort Cushion. The cushion is able to provide improved stability, reduced neck pressure, and avoid stunting with forward-facing safety seats and the WIDFIX extender. The WIDFIX Comfort Cushion uses slow rebound memory-foam to enhance optimal stable support.

After using the WIDFIX extender, the ISOFIX installation position will move outward. Generally speaking, the seat belt may not be installed correctly at the same time. We would recommend using WIDFIX PLUS, or you can go to our distributors for a trial installation before purchasing.