This is the direct thread mount for the SEG12. Our SEG12 uses the standard 1.375-24 main thread at the back of the suppressor allowing for different mountiThe Low Profile Direct Thread Mount allows for less overall length and weight to the suppressor and host firearm. Designed to be rigid, it is cut from 17-4 Stainless Steel and then heat treated to 190,000 PSI tensile strength and 47 Rc hardness. It is one tough and concentric mount. It adds only 0.100" to your suppressor. Works with any suppressor with the de facto standard 1.375-24 mount thread.ng options. These direct thread chokes use the M22-0.75 external thread.