Used to unscrew a drum trap (for old-model bath tubs) that have a recessed plug on its top. 4 sizes of plug ends on this wrench: 3/4" to 1 1/4"
Home Repair Resource Center
http://hrrc-ch.org/toollibrary/
2520 Noble Rd.http://hrrc-ch.org/toollibrary/
Cleveland Heights, OH, 44121
USA
(216) 381-6100