This sale is for a Magnaloy M300 Aluminum drive coupling hub. These have a 1-3/8" bore with a 5/16" keyway. These may be nicked up a bit and or slightly tarnished or pitted but I do not believe they have ever been used. We have quite a few different sizes we will be listing soon so please keep watching. Please see pictures and ask questions if you have them. We describe our items as accurately as possible. We do not know everything, so look at the photos as well as reading description completely. I will ship internationally and will combine shipping on multiple purchases.