For 1968-2005/2013 & later Johnson/Evinrude 1-cyl, 1.2-3.3 Hp | 2-cyl, 3-5 & 35-60 Hp | V6, 200-300 Hp outboard thermostat housings.
ID: 1.875″ | OD: 2.125″ | W: 0.125″

also crosses with:
Sierra: 18-7173
GLM: 82250
Mallory: 9-76501