Features:1. Made of high quality material, wear-resisting, safe, sturdy and durable.2. The rollers will not make any noise when it glides on the track, quiet and stable. 3. Easy and convenient to install, but profession installment is recommended. 4. Fire proof, rust proof, perfectly protect your materials from scratches or damage. 5. Ideal for sliding glass door, window and bathroom door. Specification:Condition:100% Brand NewMaterial: Plastic Color: As Pictures Shown Optional roller diameter: Approx. 20mm / 0.79'' Approx. 23mm / 0.91'' Approx. 25mm / 0.98'' Diameter of glass hole: Approx. 11.5mm / 0.45'' Thickness of wheel: Approx.6mm / 0.24'' Package list: 8 * Wheel rollers