Type B-5 pneumatic life vest.
In 1944 naval reports of Type B-4 / AN-V-18 vests providing inadequate buoyancy for heavily clothed airmen in rough seas were received by the Personal Equipment Laboratory. This input led to the development of an entirely new life vest, capable of supporting an unconscious person with his face out of the water. The project was opened in the summer months of the same year, followed by tests in November and official standardization by the AAF on 05 December 1944. The Type B-5 was born.