Fitting SizeUses1/4"Use large end to plug unwanted holes in poly mainline tubing and the small end to cap off end of 1/4" drip line..400" barb.440" Barbed Goof Plug repairs holes in mainline poly tubing for the holes made with the series 400 barb hole punch. Use Goof Plugs to plug holes in mainline poly tubing that are no longer needed.