This holster was designed in conjunction with instructors at the Special Forces Advanced Urban Combat School (SFAUC). Viper was asked to evaluate the battle belt platform and identified certain instabilities in the battle/war belt platform. Viper crafted the Tac 1 specifically to overcome these weaknesses and provide rock solid sidearm transport. The Viper chassis drops and offsets the sidearm, provides clearance and cant for quick deployment and allows lower presentation ability when necessary. The separate chassis component allows us to tune the position of the sidearm specifically to the style of the operator. All this is accomplished while stabilizing a leveraged accessory and dropping it comfortably below the tactical harness/vest or body armor carrier. Although the chassis appears to be one piece, it is actually two layers of Kydex in different thicknesses in order to provide much greater rigidity and strength than a one piece unit. The RTG HD Professional eliminates the shortcomings of the popular thigh rigs that have seen much service with elite groups. The HD Professional is in use by SWAT and DEA Drug Task Forces, state and municipal police departments and those enthusiasts who train aggressively. The holster shell of the HD PRO which is built of .125 Kydex, which is the heaviest Kydex made, to take the abuse of police and military use. They tell me you guys can break an anvil so here it is. After rigorous testing and active duty service in and out of country, we have arrived at an optimum configuration that was designed for universal application with the battle/war belt platform, rigor's belts or robust gun/duty belts that are the cornerstone of cutting edge suspension. There isn't any other holster like this in the world period. This is a superior service style holster on the leading edge of personal sidearm transport and can incorporate full muzzle capture or open muzzle as required for suppressors. Like the Tac 1, the HD Professional is wicked fast and much more comfortable than a thigh rig. When we did motion studies on the thigh rigs it was a no brainer to develop a rig that dropped the handgun but eliminated the constantly reversing inertial force that comes with mounting a handgun on the thigh. Thigh rigs are great if you don't have to move. The RTG HD Pro is so fast it has become the platform for our Evolution Competition line of wicked fast game holsters. It can also be had with Level 2 retention for those that require it. The HD Pro has recently been written up in "Preparedness Theory" by preparedness and survival expert consultant and SERE instructor Jonathan Hollerman.