Perkos Plain Manganese Bronze Rowlock Horns are available in Ribbed Type or Round Type. They are sold as a package of two and do not include Rowlock Sockets. The outer dimensions of the Shank are 1/2" and the Shank length is 2-1/8". Perkos 0828DP0PLB is a Ribbed Open Type Rowlock Horn and measures 2" between the horns.