This is spectacular. An early design 161 and old linear marks. The piece has such dimension and an old Matl feel to the form of the piece. There is 2.75in. to the inside diameter and the front face is 1.75in. wide. This is strong and well built and weighing 74 grams. The clamper is 1in. in the back. The condition is beautiful with no dents or dings and a strong spring. This is a rare, very old Spratling era clamper and made by one of the best, Los Castillo.