Premium Knees Over Toes Slant Board for Calf Stretching - Athletic Performance, Training Slant Board for Squats - Slanted Squat Board Non-Slip Surface - 25 Degree Incline, 1000 Lbs Weight Capacity. Multiple Non-Slip Features: The surface of the calf stretcher slant board is covered with a non-slip surface to prevent any risk of slipping during use.