1915-S TD.2-TD.R is a transfer die counterfeit struck on a Low Carbon Steel planchet - the only documented die struck counterfeit U.S. coin (out of 1,000+ struck counterfeit varieties) on a steel planchet!
 
This is only the 2nd documented example of this variety. This piece was actually found in a group of cast counterfeits, probably placed there due to its dark coloring. Surfaces are a little rough, and there are 2 digs on the right side rim of the obverse and one on the reverse. If you want a variety that represents the rarest planchet alloy amongst all die struck counterfeit U.S. coins, this is that rare opportunity for your collection. This piece will make it on my Top 10 list once one of those other pieces sells.