Space Saving Door Mounted Cat Shelves:Vertical door mounted cat tree takes a little space and is the best choice for small home or small apartment. Notice: Pls make sure Door Gap>3 mm, Door Thickness is 40 or 45 mm 4-levels Platform for Entertainment:Cats have incredible jumping abilities, multi-levels activity area entertains and helps cats in physical training, they do enjoy running up and down, scratching it and hanging out on the shelves as well Sturdy & Well Made & Holding up Well:It is made of sturdy multi-layer board. Each plank can support a 15 lbs cat and the whole cat tree can support 4 cats at the same time Easy to Assemble & Move:Just follow our instruction manual to finish the assembly and attach to door easily. Easy to move from room to room Perfect for Active and Height-loving Cats:Each plank can hold up to 15 lbs. The cat climber dimension is 67.3" H X 22.3" L X 10.5 W, net weight is 13.7 lbs. Give your cats 1-2 weeks to get used to it.