The Allen Engineering M24 suppressor is the modern version of the OPS INC 3rd model. The M24/3rd Model is the original suppressor all other OPS/AE models are derived from. The M24 name comes from its use on the M24 rifle system.
The M24 suppressor has our .30 caliber baffle stack shared with systems like the AEM5-30, as well as the longest AE direct thread mount. Traditionally they are mounted on a barrel that has been profiled to accept the suppressor without any hardware, however an SPR style collar can be used as well on thinner barrels.