Uprights are made of 3" (76mm) O.D. aluminum Worm gear winch elminiates dangerous backlash Nylon leader strap for safe and easy net attachment Used for all levels of volleyball, paralympic volleyball, badminton and tennis Add 438-061 Multi-Sport Winch End Upright to make a two, three or four-court setup Floor plate/sleeve not included Warranty: poles and piston, five-years; parts and winch, one-year