Clek Foonf, Mammoth (Merino wool + TENCEL® Blend)

The mother of all convertible car seats.
In stock

The mother of all convertible car seats.

The Clek Foonf convertible car seat is designed for both revolutionary forward-facing safety performance and extended rear-facing use, allowing for most kids to remain rear-facing until their fourth birthday. Featuring the NEW Merino wool + TENCEL® Blend.

Engineered to protect, it comes fully loaded with Clek’s most advanced safety features, including the patented REACT energy management system, a steel anti-rebound bar, rigid-LATCH for an effortlessly secure installation, and advanced side-impact protection, with deep side wings, energy-absorbing foam layers and an adjustable structural headrest. Plus, at less than 17 inches wide, Foonf’s narrow design makes it easy to ride 3-across. 

  • All Foonf models are free of brominated and chlorinated flame retardants, while the mammoth collection is free of any added flame retardants.
  • The Revolutionary REACT Safety System-Reducing the Forces Transmitted to Your Forward-Facing Child in a Frontal Collision.The REACT™ Safety System integrated into every Foonf convertible car seat protects your child much like the crumple zones in the cars we drive - one of the most effective innovations in automotive safety. Foonf's REACT Safety System actively reduces the forces transmitted to a child in a frontal collision. The Foonf delivers forward-facing safety performance comparable to that of a rear-facing car seat installation.
  • Extended Rear-Facing-Designed to international best practice allowing for most kids to remain rear-facing until their fourth birthday.
  • Anti-Rebound Bar-Prevents rebounding when rear-facing in a frontal collision and rotation in a side-impact collision; while also improving installation by nesting firmly and evenly into the flat part of the vehicle seat
  • Built Like a Tank-Engineered with a steel and magnesium sub-structure.
  • Advanced Side-Impact Protection System-Protects the child with its adjustable headrest, deep side wings, and dual layers of energy absorbing EPP foam for maximum side-impact protection.
  • Effortless Installation-Rigid-LATCH allows for an effortless forward-facing installation that can be done correctly (in seconds) that is so easy and so secure, you'd swear its part of your vehicle.

Clek’s Premium Fabric Collection: 

Clek’sPremium Fabric Collection features Mammoth, an environmentally-friendly blend of sustainably-sourced, biodegradable Merino wool + TENCEL® that offers improved durability and is free of any added flame retardants.TENCEL® is a trademark of Lenzing AG.

  • Free of any added Flame Retardants
  • PFOA-Free/PFOS-Free/PFC-Free/PFAS-free.
  • Fluorine-Free
  • OEKO-TEX® Standard 100 Certified
  • Made with Natural Materials
  • Hypoallergenic
  • Ethically Sourced, Non-mulesed Merino Wool
  • Best for Breathability & Temperature Regulation

Rear Facing Mode:

  • Height: 25–43 in.
  • Weight: 14–50 lb
  • Minimum Age: Able to sit upright alone

*When using with infant-thingy (sold separately), you can accommodate a child that's 5 lb and 19 in.*

Forward Facing Mode:

  • Height: 30–49 in.
  • Weight: 22–65 lb
  • Minimum Age: 2+ years recommended* (1 year minimum)


  • Age: rear-facing 14 - 50 lbs, 25" - 43" front-facing 20 - 65 lbs, 30" - 49"
  • Made of 100% merino wool, with a steel and magnesium sub-structure.
  • Rear-Facing Use: 14-50 lbs & 25"-43", (use with Clek's Infant Thingy, sold separately, for babies starting at 5 lbs & 19").
  • Forward-Facing Use: 22-65 lbs & 30"-49".
  • The narrow overall width makes 3-across seating possible.
  • Designed for extended rear-facing use—up to 50 lbs & 43" height.
  • Structural Headrest: The energy-absorbing foam-lined headrest with deep side wings is connected to frame using steel rods provides maximum head protection in a side-impact collision.
  • Energy-absorbing foam layers on both the inside and outside of the frame protect your child by absorbing energy in a side-impact collision, resulting in less force directly upon your child.
  • Rigid Sub-Structure: Reinforced by a steel and magnesium sub-structure.
  • Anti-Rebound Bar (Rear-Facing): Improves stability by limiting rotation of the child seat, helping protect your child’s head from impact in the case of a collision.
  • The REACT™ Safety System has an aluminum honeycomb crumple zone that absorbs energy and protects your child much like the crumple zones in cars—one of the most effective innovations in automotive safety.
  • Rigid-LATCH makes proper Forward-Facing installation effortless.
  • Rear-facing installation is improved with an easy-access belt path, small footprint, and Anti-Rebound Bar that provide a snug installation with ease.
  • Rear-facing base is detachable.
  • Smooth Recline: Features an easy-to-engage, smooth recline function, making each ride more comfortable.
  • Approved for use in aircraft.
  • Clek products are fully recyclable! Click here for recycling instructions on Clek's website.
  • The AAP (American Academy of Pediatrics) advises parents to keep their toddlers in rear-facing car seats until age 2, or until they reach the maximum height and weight for their seat.
  • For safety concerns, Car Seats are not eligible for return unless unused and the original packaging is unopened.
  • No flame retardants.
  • The Mammoth fabric is 100% wool. Wool is a natural flame retardant, so the foam (different from that used on the crypton fabric car seats) does not contain any flame retardant chemicals.
  • Clek uses the term "no added flame retardants" to describe the Mammoth seat because it believes that it can never be 100% sure what will be found from the environment or from cross contamination if it's seats are tested by a new party. The lab testing from a prominent U.S. lab that Clek conducts, shows that all of the major components of its Mammoth seat test free of flame retardant chemicals. 


  • Our whole collection is free of toxic chemicals (that includes the big ones you’ve heard about—BPA, phthalates, toxic dyes & perfumes, pesticides, PVC, & added formaldehyde—plus many you haven’t heard of yet).
  • Learn about Our Mission as well as Our Criteria for everything we sell.
Get Educated - Relevant Articles