Custom Grey Tubular UPVC Sight Glass sturable round borosilicate observation flow indicator liquid oil flange plastic sight glass Place of Origin:China Brand Name:KXPV Technics:Forged Connection:Flange Material:UPVC Colour:Grey Shape:Reducing Head Code:Hexagon Product name:Sight Glass Size:DN25-200 Delivery Time:7 Days MOQ:1 Piece