Product Description: - These wheels Compatible with greenhouse doors fit most greenhouses with sliding doors. Complete with bolts and nuts, convenient and easy to use. - Our wheels Compatible with greenhouse doors are made of nylon with stainless steel balls, all screws and spacers are also made of stainless steel, rust-proof and durable Compatible with long-term use. - The nylon wheel diameter is 29 mm, the inner diameter is 18 mm; The screw is M6x18; The inner diameter of the spacer is 6 mm. Universal size that fits most greenhouses with sliding doors. - The door wheel set has a long service life and a beautiful appearance, the door wheels are easy to move back and forth by sliding the door roller. - The package includes 4 pieces of nylon wheels, 4 pieces of M6x18 screws, 4 pieces of hex nuts and 4 pieces of 6 mm spacers. Package: 4x Nylon wheels 4x M6x18 screws 4x Hex nuts 4x 6 mm spacers Product Specifications: Color: White, silver Material: Nylon, stainless steel Wheel diameter: 29 mm Inner diameter: 18 mm Inner diameter of spacer: 6 mm Screw: M6x18