Enstruct tubes enstruct tubes font size 3 font color red i available now i font font p enstruct connecting tubes are made from cardboard and are completely reusable the tubes are easily cut to length using the cutting and drilling jig which is supplied in the starter kit or can be purchased separately whilst the tubes are extremely strong when used in well designed structures they are designed to fail in poor designs enstruct tubes are 1m long and are supplied in pa