Covered under Edwin McClain’s December 1928 US patent,this Hagen sand wedge has a dramatically curved face and a large, broad sole.  Bobby Jones even used one of these in the 1930 British Open.  In 1931 the USGA adopted a new regulation that made any club with a concave face non-conforming.  Consequently, Hagen stopped producing its concave sand wedge.

It was MacClain, not Sarazan, who invented the sand wedge complete with a large sole and lots of bounce. The club even bears the "sand wedge" name.  It was Sarazan who designed what would become the most popular sand wedge in the game after McClain's club was declared illegal. 

This example appears unused.  The 36" shaft and grip are original. The "LW" stamped on the back of the head indicates "Ladies Weight".  While the head is made to a "ladies weight," it is on a men's overlength 36" shaft.   Hagen Concave Sand Wedges were typically 34" to  35" in length.  It is quite possible that a lady's weight head was used to keep the weight more moderate on the longer 36" shaft.

They don't come much nicer than this...  For more info on this historic club, see TCA2 Vol. 1 p. 283-284