STRONG CONSTRUCTION: 2 high-quality ball bearings made of heat-treated bearing steel can withstand up to 265 lbs. and remain operational after 100,000 cycles of testing. Helps prevent patio doors from jamming or making harsh noises.UNIVERSAL SIZE: Package includes 2 pcs patio door rollers. They are suitable for most sliding doors and windows, such as glass sliding doors, screen doors, patio doors and sliding windows, vinyl patio doors, closets, closets and more.DURABLE MATERIAL: These tandem roller assembly are made of high quality steel that is resistant to corrosion and will not rust over time. The sliding patio door rollers are very sturdy, suitable for heavy duty use, and not easy to break and deform.EASY INSTALLATION: You just need to remove your old patio door rollers and install our glass patio door rollers, screw in the screws to complete the installation. You can easily install them on your new sliding door or use them to replace the old damaged rollers on your sliding door.SMOOTH SLIDING: This patio door rollers ensures that the patio door slides effortlessly. With a strong weight capacity of 265 pounds, these sturdy sliding door wheels can meet the needs of most windows and doors.