A male external incontinence device comprising a drainage tube assembly (5) having a proximal chamber (25) in fluid communication with a drainage tube (10), the proximal chamber (25) comprising an atmospheric equilibrium valve assembly (11). The atmospheric equilibrium valve assembly (11) has an airway conduit (12) with a upper portion (13) in fluid communication with the proximal chamber (25), and a lower portion (14) having an air inlet chamber (15). A one-way air valve (16) disposed in the airway conduit (12) above the air inlet chamber (15), the one-way air valve (16) comprising a first pair of opposing walls (17) disposed at a first set of opposing angles (18) such that the first pair of opposing walls (17) abut each other at an apex (19), the apex (19) having a self-sealing slit (20).
