A Polyethylene, 1 pc. tank in the exact same shape and size as the original. A 21 gallon tank with almost 1/4" thick walls. This tank can also be used on older pickups for those who want to remove the tank from behind the seat. ( Will also work on 69-70 trucks with minor modifications.) 12 3/4 x 16 1/2 x 26 inches.