Image Cam & Groove In-Line Sight Glass Coupler x Coupler Markets Dry Bulk Cargo Truck Jump to Section Product Options Related Products Product Options Part Number Coupler Size Seal Material 3533CC 3" x 3" Nitrile Rubber Aluminum 3543CC 4" x 3" Nitrile Rubber Aluminum 3544CC 4" x 4" Nitrile Rubber Aluminum Related Products Image Cam & Groove Adapter x NPSM Thread Image Cam & Groove In-Line Sight Glass Adapter x Adapter Image Cam & Groove In-Line Sight Glass Coupler x Adapter Image Cam & Groove In-Line Sight Glass Repair Kit Image One-Piece Aluminum Butterfly Valve with Iron Disc