... 4.shock absorbent Product Name: 2000BB-Wheel Nylon Sliding Pulley, Plastic Shower Door Roller Professional supplier: over 5years in bearings, pulleys,rollersPopular ... Glass Open-Hole: 12mmApplication:Aluminum frame, Glass door, bathroom door, shower room door 2000BB-Wheel Nylon Sliding Pulley, Plastic Shower Door Roller