LegWorks’ ATK (all-terrain knee) HydraPro is a low-maintenance, waterproof, and highly functional 4-bar prosthetic knee joint that is designed to meet the physical demands of active amputees; it is offered with or without stance flexion. The company’s patented Autolock Technology stance phase controller is engineered to give the user confidence on all terrains, while the Hydraulic Variable Cadence Controller (patent pending) allows for multiple walking speeds. Described by LegWorks as an ideal knee for K3- and K4-level ambulators who desire a water leg, the ATK HydraPro includes a simple twist-knob manual lock that allows for stability in or around the water. The product ships with a blue cover installed; an alternate black cover is included. Designed to handle up to 330 pounds, the ATK HydraPro comes with a 24-month manufacturer’s warranty.