Ideal for the visual inspection of liquid refrigerant or oil levels, Heldon nowoffer a complete range of plated steel bodies, MNPT threaded, Sight Glasseswith built-in fused lense. Suitable for a wide variety of pressure vesselapplications, these sturdy items are suited for most refrigerants and oils.ApplicationsSight glasses are used in refrigeration and air conditioning systems for bothliquid refrigerant and oil applications.The SG-12 series sight glasses are suitable for HCFC and HFC refrigerants,along with their associated oils.The SG -10 and SG -11 series sight glasses are suitable for HCFC, FC andammonia refrigerants, along with their oils.Features• Three sight glass lens options - Reflex, Clear and Clear with float ball.• Hermetically sealed fused glass construction.• Plated Steel body