The Amphibian boots from Fourth Element redefine comfort in diving footwear and are the only diving boots in the world to feature removable ergonomic footbed insoles. This provides heel support and impact protection, arch support and cushioning underfoot. The stiff chassis enhances stability and increases comfort when climbing a ladder or shore diving carrying full kit. The midsole provides additional cushioning underfoot from impact and uneven surfaces. The footbed incorporates a heel cup for heel support, arch support and additional protection from sharp objects underfoot. Additional cushioning directly below the heel provides added impact protection when walking carrying dive equipment. The boots have a double layer of reinforcement on the top of the boot protecting the foot from pressure of the fin's boot pocket and enhaning comfort. It is made using recycled materials. The Fin-strap Retainer does exactly what is says, keeping the strap up on the back of your heel. This has been carefully researched and tested to work with most diving fins on the market today. The cut-away at the back of the heel minimises stress on the Achilles tendon during finning, ensuring greater comfort during longer dives. A common problem with dive boots is having the zip slide down during a dive, letting water in and making your feet cold. The heavy duty zip and in particular zip-stopper reduce the risk of this happening, keeping the top of the boot tight around your ankle.