Product size: Bi-fold door guide wheel hardware kit fits doors from 1 inch to 1-3/8 inch thick. Guide wheel is 2 inches long, wheel OD 7/8 inches, shaft OD 3/8 inches; top pivot is 2 inches long, metal head OD 1/4 inches, shaft OD 3/8 inches. Please check the size chart before purchase. Reliable material: Closet door rollers are made of high-quality nylon, stainless steel, and hard plastic. Precise sizing, well-made construction, and reliable quality ensure waterproof and moisture-proof performance. These materials prevent breakage from frequent sliding, ensuring long-term use. Easy to use: The guide wheels in the kit feature built-in springs that secure them to the door opening. Press the spring to gradually adjust the distance between the door and track, allowing quick installation into the bracket and track. Efficient repair: This bi-folding door hardware kit allows for fast replacement and repair of damaged or worn doors without replacing the entire door. Suitable for repairing bi-folding closet doors, sliding doors, and cabinet doors. The bifold door top guide wheel is a common replacement part for such applications. Made with high-quality materials, precise dimensions, and excellent craftsmanship to save time on repairs. Quantity: 4PCS or 8PCS Color: As shown Material: Metal + Plastic Package Contents: 4 x Bi-Fold Door Top Roller Guide Wheel and Top Pivot or 8 x Bi-Fold Door Top Roller Guide Wheel and Top Pivot. Only the items listed are included; other products are not included. Note: Lighting effects and display settings may cause slight color variations between the image and the actual item. Measurement allowance is +/- 1-3 cm.