Oil level Sight glasses, sight gauge, sight gage, oil level indicator, liquid sight glass, sight window, view ports, male thread sight glasses Body material: aluminum, brass, PC, PPMA and steel Glass: Real glass 2 mm to 5 mm thickness. O Ring: Viton O rings Size: M10 to M42, 1/2 inch to 2 inch Thread Type: NPTF, NPT, UNC, UNF, Metric and BSP (G thread) Operate Temperature: -20 cent degree to 120 cent degree Operate Pressure: 5-10 Bar or 0.5MPa to 1 MPa. MOQ: 2000 Pcs each size Delivery time: 20 days. Payment: T/T Usage: Pump,Oil Receivers,Gearboxes, Speed Reducer, Compressor and Power Transmission. Different company have different requirements, OEM Service is welcome.