6" Tri Clamp x 30" Column Cooling Coil with Dip Tube Hoses 4" x 48" Tri Clamp Spool Recovery Pump 4" x 48" Tri Clamp Spool The stainless steel rings are solid and measure 8mm in thickness and the filter plates measure about 3mm in thickness with 6mm holes This cooling coil is made out of 304 stainless steel and has a 3 8" diameter coil spiraling from (3) 1 4" FNPT ports on the top with 2 of them connecting to the coil and one of the connecting to the dip tube This column cooling coil is designed to fit in 6" Tri Clamp material columns and allows the user to either chill or heat the column up from the inside which increased the surface area beyond a standard dewaxing jacket and reduces the need for dry ice