OPS INC™ SPR Collar for Daniel Defense MK12

The DD SPR collars were made specifically to work with the Daniel Defense MK12 to allow mounting of an A length suppressor like the AEM5. Made to the same standards as the standard MOD1 SPR Collar, the taper offset has been adjusted to work with the step on legacy Daniel Defense MK12 barrels that have a 2.3″ offset from muzzle to the locating step in the barrel. Use these in combination with an OPS INC brake.

According to Daniel Defense the barrels were updated 5/9/2022. So any barrel manufactured after that date should have a standard SPR profile. However they did not scrap inventory, so there are barrels that were sold after that date with the old geometry. You should be able to know manufacture date from the barrel serial number which always starts with month and year “MMYYXXXXX”

If you want to be sure before purchase, verify the length of the offset in the barrel. You can do this by measuring the distance between the muzzle and the step in the barrel. If it is 2.3″, use the DD specific collar. If it measures 2.4″, you can use a standard SPR collar.