Socket for cleanout plugs with 1-1/4" x 1-1/4" square raised head. Can be used with the T-handle supplied in the kit (or sold separately) or a standard 3/4" socket wrench. 
 
Works great for 3-1/2" and 4" cast iron cleanouts as well as 2" PVC cleanouts. May work with other sizes as well. 
 
PN3