Turn-pin spectacles featured an extension on the end of the temple. The extension was held in place by a rivet. The extension would rotate 360 degrees. The proper position for the turn-pin extension was upward around the 1 o’clock position. The extension was often formed to fit the crown of the owner’s head. This type of spectacle tended to stay in place better than straight temples and sliding temples. The turn-pin spectacles was made from the early 1760’s to around 1880.