Connection device

Abstract

Connection device (1), in particular for an injector, with a connection piece (5) and a fastening device (10), wherein the connection device (1) further comprises an elastic locking element (15) such that in a first position of the fastening device (10) with respect to the connection piece (5) the locking element (15) is in an unlocked position and that in a second position of the fastening device (10) with respect to the connection piece (5), which differs from the first position, the locking element (15) is in a locking position, characterized in that the locking element (15) is designed as an O-ring or as a ring with non-connected ends, in particular made of plastic or metal.