Abstract: A coupling device for a fluid pressure system comprises a housing (8) receiving a coupling body (2), and means for retaining the body (2) in the housing (8), the retaining means comprising a grab ring (36, 60, 61) having radially inner teeth (43) for engagement with the body (2) and radially outer teeth (44) for engagement with the housing (8), the grab ring (36, 60, 61) being mounted in a groove (39) in the body (2), and the grab ring (36, 60, 61) and the groove (39) being so constructed and arranged that on insertion of the body (2) into the housing (8) the outer teeth (44) are deflected by the housing (8), but on application of a removal force the grab ring (36, 60, 61) pivots in the groove (39), urging the inner teeth (43) into engagement with the body (2) and the outer teeth (44) into engagement with the housing (8).