This gasket is designed to meet the original equipment specifications for its designated valve series

What is the difference between nominal and OD for this part

75-inch probe

you should look for the 133392A O-ring assembly or the 4074EYK/EYL kits depending on your specific valve body size

Optimized Probe Depth: The 3" insertion depth reaches the ideal sensing zone within the furnace cabinet for reliable temperature monitoring

Lochinvar & A.O. Smith 100147003 Temperature Gauge This gasket is designed toThe Lochinvar & A. O. Smith 100147003 Temperature Gauge is a critical monitoring component designed for precision thermal tracking in high performance hydronic systems. This 2 1 2 inch dial gauge provides an accurate readout ranging from 50F to 266F (also rated for 0 250F in specific applications), ensuring your boiler or water heater operates within safe thermal parameters. As a direct OEM replacement part, it is 100% identical to the GTP3000,