This is an impressive example of the circa 1910 forked-hosel Otto Hackbarth "patent" putter. The maker's mark an the "Pat 687539" are very bold on the sole of this Aluminum putter. The putter also includes a heel-to-toe Lead inlay to add weight to the otherwise aluminum putter. Unlike many Hackbarth Patent Putters, the Hackbarth name and Patent number are not obstructed by the lead inlay. Very good condition.