Heavy duty carbon steel track kit covered with black powder coated surface ensures water resistant and rust proof for long lasting use. Max Door weight capacity is 330 lbs. Adjustable roller screws fit Door Thickness from 1.2″-2″(30-50mm). Track width is 1.57″/4cm, thickness is 0.24″/6mm. Diameter of the roller. Super silently nylon wheels bring no noise when sliding your door. Spring damping door stopper make the close more softer and comfortable. T-Shaped floor guide can keep the door stable and prevent door bottom from swinging back and forth. Tep-by-step installation instruction very easy to install. Intimate 24-hour online customer service. Upgrade spring design for effective shock. Absorption, door protection and noise reduction. Add anti-falling wheel on the roller, can effectively prevent the roller hange. R from falling off during slidin. Ngle Door Track Kit. 2 PC (1 PAIR). 4 PC (2 PAIR). How to Choose the Correct Track Size? Door Min Track Size= 2 × Single Door panel Width. Example: For a 36″/3FT door, recommend you choose a 72″/6FT track at least. Door Min Track Size= 4 × Single Door panel Width. Example: For a 36″/3FT door, recommend you choose a 144″/12FT track at least. Tip: If you have enough space you can also choose the longer track size. Small roller is 2.75 inch/7cm.