Excellent setup for the tall, heavy pre-depression upright pianos. Rated for 160 pounds each caster. Rubber wheels are easier on most floors and won't leave rust stains on carpet. Kit includes bushings for the socket stems (in case existing hole in piano is larger than the 1/2" new stem - very important to prevent breaking socket). Cardboard shims also included in the event they are needed to level the piano. Screws are number 10 size, 1.5" long. Original screws are often bent, missing or rusty. Halfway through the job is not the time to find out you need any of these parts. Caster plates/sockets are 2 1/8" diameter. The stem that fits up in the piano is almost 5/8" in diameter (.59") and is 1 7/16" long. The caster wheels are 2" in diameter and a little over 3/4" wide (26/32" to be more precise). The dual wheel casters are 1 26/32" wide. The distance from the mounting plate to the bottom of the wheel is about 2 3/4". The included bushings force fit over the stem and have an outside diameter of .92" - useful when replacing original casters that had a larger diameter stem. For longevity of the caster socket it is important the stem fits tightly in the body of the piano