Abstract: A spray gun or fuel nozzle wherein the underside of the pistol grip handle is formed with a socket for a rotary insert which is connected to two or more supply conduits for flowable materials. The insert has passages which convey flowable materials from the respective conduits to discrete channels in or on the housing of the gun or nozzle. One of the passages can extend from the respective conduit to the inner end face of the insert to admit flowable material into a channel of the handle, and one or more passages can extend from the respective conduit or conduits to annular spaces which are provided in the peripheral surface of the insert and/or in the adjacent internal surface of the handle and each of which communicates with a discrete channel. At least one channel can be provided in a guard in front of the trigger which is actuatable by the hand holding the handle.