The invention relates to a coupling device with a housing and a locking element for receiving a cylindrical connecting element, whereby an operating element for the releasing of the locking element is accessible by way of an opening in the housing and whereby the locking element includes at least one holding portion, whereby the locking element includes a first spring arm with a holding portion which arm extends from the operating element all the way to a wall of the housing opposite the operating element, whereby the spring arm is constructed at the opposite wall with a joint portion.