Amazon.com: 1"NPT Male 304 Stainless Steel Oil Sight Glass Hex Head Sight Plug Liquid Level Gauge Oil Indicator Sight Window for Air Compressor Gearbox Fittings Hydraulic Tank (1pcs 1 NPT Stainless Steel)
Sight Glass | 7.5” - Ss Brewtech
K9900 Level Series Gauge | KENCO
TC Sight Glass | Spike Brewing
Flow Sight Glass, PN6 Easy Installation Stainless Steel in Line Clear Viewing Sight Glass with Clamp End for Oil(57mm / 2.24in): Amazon.com: Industrial & Scientific