1 7/16" (36mm)
By Seiko Precision. 1 7/16 outside diameter and fits a 1 3/8 hole. Gold bezel with either white or gold face, Arabic or Roman. Metal alloy case with glass crystal. High quality movement. Easiest way to change the battery in the industry, there is a rubber battery cover on the back that comes off and the battery is inside. Stainless steel back. This is the best quality insert on the market.