The Gravity Boots from Hang Ups feature: Dual, self-locking ratchet buckles Unique double-lock system for security Unparalleled comfort Super-soft 5/8 foam liners are a special blend to give maximum comfort with minimum compression Flexible shell Made of light, highly durable DuPont Hytrel material for a comfortable fit Exclusive calf loops Removable feature place a 2 degree bend in the knees to help reduce the load on knee joints and the top of the foot Strong, durable materials Hooks and calf loops are made of 40% glass nylon alloy, creating a stronger product 5-Year Warranty 30-day money-back guarantee Packaged dimensions: 6.5" x 9 x 12.75" (16.5 x 23 x 32.4 cm) Packaged weight: 5 lbs