The Propper ACU pants are pants specifically made to be worn by the US Army as their official pants of the battle uniform. ACU is short for Army Combat Uniform, the new standard battle uniform replacing the old standards, the Battles Dress Uniform (BDU) and the Desert Camouflage Uniform (DCU). The ACU completely replaced the BDU in December of 2007 after being introduced in 2004. The standard army issue ACU uses a camouflage pattern called Universal Camouflage Pattern (UCP) or sometimes commonly referred to as Army ACU digital camouflage and is comprised of the colors slate grey, desert sand and foliage green in a digital pattern. The ACU is also issued in other camouflage patterns such as digital desert camouflage, digital subdued camouflage, digital woodland camouflage and mulitcam camouflage though the Universal Camouflage pattern is used by the US Army. The newly added features to the ACU pants that werent available with the BDU pants are as follows knee pouches to insert knee pads, elastic leg cuffs, forward tilted thigh pockets equipped with elastic draw strings and Velcro for closure, and two calf storage pockets with Velcro closure. According to Army specifications (AR 670-1) there is an option to have pants legs bloused but can not extend beyond the third eyelet of the boots. Besides the original ACU pants, there are two additional designs, a fire resistant pair of ACU pants and a bug repellent pair. The flame resistant ACU (FR ACU) is constructed with defender M which features Lenzing FR fibers, a fire resistant and self extinguishing fabric that will not melt or drip when in contact with open fire. The fire/flame resistant properties are part of the fabric, therefore it will never wash or wear out. The defender M fabric is comfortable and lightweight fabric with breathable Lenzing FR fibers that keeps you cooler by absorbing perspiration faster. Lenzing FR protects the skin from all kind of heat, fire, radiant heat, electric arcs, molten metals and flash fires. The FR ACU is built to military specifications (FQ/PD 04-05A) and is Near Infrared (NIR) compliant. The No Fly Zone ACU pants are ACU pants treated with Permethrin, an insect repellent. Permethrin repels against mosquitoes, ticks, ants, chiggers, flies and midges and also is built to military specifications (FQ/PD 04-05A). Permethrin is crosslinked onto fabric during before the manufacturing of a product to ensure a consistent application, after 50 washes certain fabrics contained as much as 83% to 87% Permethrin. Permethrin is registered with the Environmental Protection Agency (EPA) and tested by the US military. Proppers ACU pants are commonly seen worn among soldiers part of the battle uniforms. Depending on the soldiers location he can choose between the original ACU pants, the flame resistant ACU pants, or the No Fly Zone ACU pants. ACU pants are also seen being worn by civilians for comfort, design and also for tactical operations. The flame resistant and no fly zone ACU pants can be useful to professionals who are subjected to open flames or to insects. The ACU pants offered by Propper International are also commonly referred to as ACU pants, ACU trousers, acu camo pants, acu digital camouflage pants, digital ACU pants, army combat uniform pants, army combat uniform, the ACU, acu digital slacks, new army digital pants in ACUPAT, ARPAT, official universal camouflage, acu digital camouflage, army digital, new army camo pants, genuine army uniform pants, military fatigues, camo trousers bottoms, army surplus fatigues.