The UMP (Universale Maschinenpistole, German for "Universal Submachine Gun") is a submachine gun developed and manufactured by Heckler & Koch. The UMP has been passed the combat test of U.S. military and adopted by various agencies such as the U.S. Customs and Border Protection, Heckler & Koch developed the UMP as a lighter and cheaper successor to the MP5.
There are three versions of the UMP: Apart from the different chambering, all versions feature the same basic design, the most noticeable difference being the curved magazine used on the UMP9, whereas the UMP40 and UMP45 use a straight magazine. All three versions of the weapon can be converted to any of the available chamberings through replacement of the bolt, barrel, and magazine.