Decompression locks are required in order to achieve a rapid compensation of pressure in case of a sudden increase in pressure in one of two areas which are separated by a pressure tight wall. Decompression locks are used where different pressures in two separate areas have to be compensated rapidly. The purpose of this invention is to provide an improved decompression lock or an improved structural unit with two adjacent decompression locks acting in opposite directions. The improvements include a reduction in weight, simplified installation, a lower number of constituent parts, and a resulting reduction in overall cost.