Used Harbinger AB Carver Pro W Knee Pads Ab Roller Exercise Wheel Black 3 Medium Low cut V Shaped Back 31 18.5:orange Medium Low cut V Shaped Back Accurate and consistent sight with advanced tool less micro windage and elevation adjustments Increased accuracy with convenient laser engraved reference marks Prevent binding over time from dust and dirt with nylon bushings Increased strength with aluminum encased biscuit Silent arrow loading with custom rubber boots Ultra wide ab roller with built in resistance and ergonomic handles to help maximize results of ab roll out exercises Interior kinetic engine uses a carbon steel spring to provide resistance and amplify abdominal and arm workout Ultra wide wheel tread offers stability when carving left right or center for targeted work on obliques Ergonomic hand grips are angled to activate arm and core muscles handles are removable for easy storage and transport Includes high density foam kneepad for superior comfort