Gemtech Integra 556, Integrated Suppressed AR-15 Upper Receiver, 556NATO, 10.5 Barrel Length, 16.1 Overall Length, Titanium, Black Finish 12112 The GEMTECH INTEGRA upper series is the most advanced Integrally Suppressed Upper Receiver available. Gemtech has teamed up with NEMO Arms to create the smallest and easiest to maintain package the world has ever seen. The INTEGRA utilizes GEMTECH's proven G-CORE Technology that is removable, cleanable, and replaceable while still bringing the best sound reduction of any similar sized package. The GEMTECH/NEMO Arms patented gas block eliminates blowback, making this upper receiver more comfortable to shoot. The Innovation, Accuracy and Quality is what makes GEMTECH, The Professional's Choice for Decades.