Sight glass 1 3/4" UNF for skrol compressors, with Teflon seal. Production 8/2009 and later. ZP232, ZP233, ZP292, ZP293, ZP385, ZP485, ZB11M3E, ZB220, ZB56, ZB75, ZB92, ZF24, ZF33, ZF40, ZF48, ZH100, ZH11, ZH125, ZH150, ZH24, ZH33, ZH40, ZH48, ZH56, ZH75, ZH92, ZR11, ZR12, ZR16, ZR19, ZR250, ZR310, ZR380
