Once used as shorthand symbol in astronomy, the male symbol now commonly signifies gender. Perfectly engineered to securely hold the Male Symbol Fancy Stone, there are three versions: the unplated 00 C has no holes and a closed back, and is mainly used for soldering and post-plating in the jewelry segment. The unplated, gold-plated, or rhodium-plated H2 O has holes and an open back, and is largely used in sewing. 1T O comes in the same three plating options, but with a ring on top and an open back, lending it to hanging projects (rather than sewing), and especially suitable for DIY.