Master Mechanic, 4 Piece, I/M Coupler & Plug Connection Set, Includes 1 Each 1/4" I/M x 1/4" NPT Female Industrial Coupler, 1/4" I/M x 1/4" NPT Male Industrial Plug, 1/4" I/M x 1/4" NPT Female Industrial Plug, & 1/4" NPT Male Hex Nipple, Pre-Applied Teflon Thread Sealant.