Deluxe Indoor Aluminum Tennis Post is a smaller version of the Gared volleyball system and is ideal for multi-sport facilities, 4"" O, D, upright is constructed of a strong, yet lightweight anodized extruded aluminum for superior support and long life, Easy-to-operate ratchet winch sets net tension, Exclusive wedge lock holds sliding rail system securely, Uses 3, 5mm Polyethylene Edward"s Tennis Net (sold separately), SKU: GSPRT150