The case is made from 7mm Astroboard, a lightweight but very strong polypropylene honeycomb material. The case is fitted with interlocking aluminium sections to the joint edges to give a splash proof seal. Edges are fitted with 22 mm aluminium angle. Zinc coated pressed steel ball corners and edge brackets will increase strength and protection. The lids are secured to the case with four mini butterfly type catches. Internally the case has no lining. Internal measurements are W185 x H90 x D575mm (including lids), small lid is 50mm deep and larger one is 140mm deep.