In order to create a quick-acting connection which is secure and subject to low levels of wear, in particular for the purpose of filling gas cylinders, having a housing (1), having an inlet (2) and an outlet (3) for medium which is to be transferred, and having a quick-acting-connection device (4), in particular with collet chucks (5), provided in the region of the outlet (3), and having an actuating means (7), which engages in a recess (8') of a sliding sleeve (8) by means of an eccentric disk (12), it is proposed that the recess (8') contains a sliding block (9), to which the eccentric disk is eccentrically coupled and which, when the actuating means (7) is pivoted, can be displaced transversely to the longitudinal axis (f).