4" ID x 4.584" H detachable collar. Mold volume of 1/30 cu. ft., cold-rolled steel tubing, plated for rust resistance. Mold has vertical split in body with 2 quick-acting clamps for easy removal of specimen. Clamps are rotated 15� off base plate corners for easier installation on automatic mechanical compactors. Steel base plate is 6" x 6" x 1/2" thick.