Standard 304 Stainless Steel Liquid Level Gages can be used on hydraulic reservoirs, gearboxes, bearing housings, crankcases, transformers and machinery oil reservoirs.  Their use can be extended to any industrial liquid level viewing application.  Fluid enters through the cross hole in the hollow lower bolt and the gage is vented into the tank through the cross hole in the top bolt.   The length between the center of the two bolts is referred to as the centerline.  Centerlines are available from 3" to 60". 
Items
YB4054-0300B 316 SS Standard LLG 3 CL Front Mount

304 Stainless Steel Liquid Level Gage, 3” Centerline, Front Mount 1/2”-20

YB4649-0300BW 316 SS Standard LLG 3 CL Back Mount

304 Stainless Steel Liquid Level Gage, 3” Centerline, Back Mount 1/2”-20 with Nuts

YB4054-0300B 316 SS Standard LLG 3 CL Front Mount

304 Stainless Steel Liquid Level Gage, 3” Centerline, Front Mount M12 X 1.75

B4762-10300BN1W_Standard 3 CL .25 Male NPT w Adapter

304 Stainless Steel Liquid Level Gage, 3” Centerline, 1/4" Male NPT Adapters

B4762-10300BN2W_Standard 3 CL .375 Male NPT w Adapter

304 Stainless Steel Liquid Level Gage, 3” Centerline, 3/8" Male NPT Adapters
Centerline N/A 3"
Mounting N/A 1/2"-20 N/A 1/2"-20 with Nuts N/A M12 X 1.75 N/A 1/4" Male NPT Adapters N/A 3/8" Male NPT Adapters
Feature N/A Standard
Max Pressure N/A 125 PSI
Max Temperature N/A 225° F
Seals N/A Buna-N
Body Material N/A 304 Stainless Steel