recoil of the firearm, and the dedicated mounting hardware also adds to the price. One downside of the weapon-mounted light is that it is always aimed parallel to the bore, so illuminating an object means that it is also targeted. Because of this, weapon-mounted lights may not be appropriate under some rules of engagement. Weapon-mounted lights used to be specific to particular models of firearm, and to some extent that is still true; for example, SureFire makes dedicated lights that replace the forends of the Mossberg 500 and Benelli M3 shotguns, the Heckler & Koch MP5 submachine gun, and the M4 carbine. On the other hand, many modern firearms are incorporating rail integration systems, allowing any appropriately-sized rail-compatible tactical light to be attached. Other mounting systems are simple clamps, designed to mount most cylindrical lights parallel to the barrel of most firearms. Using an infrared light in conjunction with night vision goggles can mitigate concern about revealing the user, so long as the target lacks night vision. Also partially mitigating this risk associated with a visible light tactical light is the ability of the tactical light user to temporarily disrupt the night vision of the target. Standard form factor and light bearing holsters On most handgun holsters, the firearm is held in the holster via the trigger guard, either via a locking mechanism or simply by the holster being a bit tight in that area and holds or clicks the firearm in place. On handguns with lights, however, it is often not possible to make a holster that retain the firearm by the trigger guard, and most such holsters therefore retain the firearm firmly via the light. As such, ready-to-use light bearing holsters not only have to be made for a specific handgun model, but also a specific light, or at least for a light which shares the same or roughly the same form factor. One example of this is the SureFire 300 and 400 model series, which have retained the same form factor despite receiving numerous modifications over time. Pistol lights sharing the same form factor gives the possibility to upgrade lights to newer models and continue to use old holsters, as well as giving better aftermarket support for holsters. Some holsters can safely accommodate different types of lights. Lighting features Since tactical lights are intended for use in situations where lethal force is likely to be used, reliability