The bottom two drawers of my dresser have been broken for 15 years (dresser bought from Lacks in 1996 as a bedroom set). I didn't know what these things were called and looked everywhere for drawer slides. I even considered buying some of the other types which are significantly more expensive and much more difficult to install. Boy am I glad I finally found her! They come in packs of two so you can attach two drawers with one pack if you only have one drawer in each drawer. I undid the center screw and replaced the part in the dresser in less than 30 seconds. The two screws on the drawer took a little longer because I was tightening the rail which opened a little, probably because the front had broken in 15 years! each with added time to compress and install, compress and install, compress and install until I pressed hard enough, I still have the part that comes in the box back in place in just over two minutes. I don't know if I need to do this, but I wanted to make sure the drawer slides were well supported. For less than $3 per drawer and less than 3 minutes per drawer, I was FINALLY able to fix dresser drawers! The dresser is in great condition although the style is a bit dated making it look like a brand new dresser again! So happy I found her! (PS. I wrote the model number on the back of the box where the square is with an indelible marker so I never forget, and bought an extra set just in case!)