Tandem Window Rollers. the wheels are brass and has Double wheels. these rollers are to go under a sliding window.
this will let the window sash move more easier as you open the window.
Roller size INTER BASE 1 3/8" long 3/8" wide Top Base 1/2" wide 1 7/8" long
the rollers are sold as a set of 2 each.
If you have any questions, please let me know how I can help.
D