A fitting is provided that includes a receptacle having an inner wall forming a female member. The inner wall includes a shoulder and a land. A male member is received in the female member with a gap therebetween. The male member includes an outwardly opening groove. An O-ring is seated between the outwardly opening groove in the male member and the shoulder and the land of the receptacle to prevent removal of the male member from the receptacle. The outwardly opening groove, the shoulder and the land are configured such that compression of the O-ring is sufficient to prevent removal of the male member from the female member.