Basement Tanks 400 gallon... 14 gauge... 27"x44"x90"... 275 gallon... 14 gauge... 27"x44"x60"... 220 gallon... 14 gauge... 27"x44"x48"... 135 gallon... 14 gauge... 27"x44"x30"... *275 gallon... 12 gauge... 27"x44"x60"... *U.L. Listed Standard fittings 2" vent 2" fill for gauge, and 1/2" drain in the bottom of tank.