They are not compatible. They each perform a different purpose and those purposes oppose each other. There are a lot of worthless dual units out there that are sold for looks not function. The flash hider is to hide the flash from the shooter not someone on the other end. The muzzle brake reduces recoil by redirecting the gas at the muzzle and will increase the flash seen by the shooter. Shoot them both in dim light or in the dark and you will see the difference. Shoot the flash hider first because you will blind for a bit after shooting the muzzle brake in the dark. Do not put a muzzle brake on a firearm that you might have to use at night. Learned this the hard way.