round observation ports, NPT sight glass windows, reservoir oil sight glass, hydraulic tank oil sight glass,Ölschaugläser

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 Celsius degree to 120 Celsius 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, Thin-wall container, Radiator,Hydraulicreservoir, receivers,Gearboxes, Speed Reducer, Compressor and Power Transmission.

Different company have different requirements, OEM Service is welcome.