Image Coupler x Adapter Sight Flow Indicator Markets Petroleum Cargo Tanks Jump to Section Product Options Related Products Product Options Part Number Coupler Size Adapter Size Seal Material 5201CA 4" 4" Baylast™ Aluminum 5201CA-3 3" 3" Baylast™ Aluminum Related Products 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 Coupler x Coupler Image Coupler x Coupler Sight Flow Indicator Image TTMA Flanged Short Sight Flow Indicator Image TTMA Flanged Sight Flow Indicator