The SU-III RWRT is a top-opening blast and gastight shelter hatch designed for protected facilities and civil defence shelters. According to the published product description, the hatch is designed for blast pressure of up to 440 kPa (4.4 bar) and is intended for horizontal, top-opening installation. Atmas Group The product is available with different clear opening dimensions and can be installed either during new construction or as a retrofit solution. SU-III RWRT — product