Feature: Welcome to our shop 1. This mobile vertical ladder slide rail track can not only be used to fix the ladder, it can also be used for the classic barn door roller of the sliding ladder (not only can be used to move the ladder, but also can move the barn door to fix the door panel On the track, but the size of the door needs to be measured in advance) 2. Are you still worrying about how many people work together to carry a heavy ladder every time you need to reach a higher positionThen this mobile straight ladder slide rail hardware kit will solve this trouble for you 3. If you can't find the size on the size chart, please tell us the railway size you need, and then we will send you the price and order link, or you can combine the size you need by choosing a small size (100cm) Product Name: Mobile Slide Rail Hardware Set Material: special alloy steel Dimensions: 150cm(5ft), 200cm(6.6ft), 244cm(8ft), 300cm(9.8ft), 340cm(11.2ft), 366cm(12ft), 400cm(13ft), 488cm(16ft) Weight: 4.3KG/9.5ibs Maximum load: 150kg/330ibs Installation: Please refer to the installation guide and installation manual , the installation is convenient, and it takes up to 2 people to complete the installation Packing: 39 3/4 inch (1000 mm) track, a pair of pulleys, a pair of bottom rollers, two stoppers, two end caps and all required screw accessories, etc. Note: Manually measure the size, there may be an error of 1-2cm, please refer to the actual product This product has only the ladder track hardware kit, does not include ladders, bookcases, books, etc