By the 1980s, the demand for new submachine guns was very low and could be easily met by existing makers with existing designs. However, following H&K's lead, other manufacturers began designing submachine guns based on their existing assault rifle patterns. These new SMGs offered a high degree of parts commonality with parent weapons, thereby easing logistical concerns. In 1982, Colt introduced the Colt 9mm SMG based on the M16 rifle. The Colt SMG is a closed bolt, blowback operated SMG and the overall aesthetics are identical to most M16 type rifles. The magazine well is modified using a special adapter to allow the use of the smaller 9mm magazines. The magazines themselves are a copy of the Israeli UZI SMG magazine, modified to fit the Colt and lock the bolt back after the last shot. The Colt is widely used by US law enforcement and the USMC. 1990s In 1999, H&K introduced the last widely-distributed SMG, the UMP "Universal Machine Pistol". The UMP is a 9mm, .40 S&W, or .45 ACP, closed-bolt blowback-operated SMG, based on the H&K G36 assault rifle. It features a predominantly polymer construction and was designed to be a more cost effective, lighter weight, and less complex design alternative to the MP5. The UMP has a side-folding stock and is available with four different trigger group configurations. It was also designed to use a wide range of Picatinny rail mounted accessories 2000s In 2004, Izhmash introduced the Vityaz-SN a 9 mm Parabellum, closed bolt straight blowback operated submachine gun. It is based on the AK-74 rifle and offers a high degree of parts commonality with the AK-74. It is the standard submachine gun for all branches of Russian military and police forces. In 2009, KRISS USA introduced the KRISS Vector family of submachine guns. Futuristic in appearance, the KRISS uses an unconventional delayed blowback system combined with in-line design to reduce perceived recoil and muzzle climb. The KRISS comes in 9mm Parabellum, .40 S&W, .45 ACP, 9×21mm, 10mm Auto, and .357 SIG. It also uses standard Glock pistol magazines. 2010s By 2010, compact assault rifles and personal defense weapons had replaced submachine guns in most roles. Factors such as the increasing use of body armor and logistical concerns have combined to limit the appeal of submachine guns. However, SMGs are still used by police (especially SWAT teams) for dealing with heavily armed suspects and by military