Double zinc alloy wheels, thickened zinc alloy frame has excellent corrosion resistance, the solid frame is resistant to breaking and cracking. Adopt the cylinder as rolling body, evenly stressed and quiet; keep it smooth when rolling The thickened zinc alloy frame has excellent corrosion resistance, and the solid frame is resistant to breaking and cracking. Body strong roller, the entire zinc alloy pulley is evenly stressed, rolling smoothly, strong, firm and durable The design of the roller self-adjustment function, with its own function adjustment, can automatically adjust to ensure the horizontal movement of the pulley according to the tilt of the window. Product Name: Window Pulley; Material: Metal Color: silver tone; Hole Spacing: 55mm / 2.2" Hole Dia.: 4mm / 0.16"; roller size (each): 12 x 8mm / 0.64" x 0.31" (D * T) Total size: 68 x 16 x 15mm / 2.7" x 0.64" 0.59"(L*W*T); Weight: 59g Manual measurement may have deviations Package Contents: 1 x Window Pulley Designed with double silver metal roller, easy and convenient to use an ideal accessory for your door, window, etc.