3P15 a 1/2 x 28, 5.56mm Plan B compatible flash suppressor / sound suppressor mount, a collaboration is  between Revival Defense and Forward Controls Design.

While their tried and true 6315 design provides both effective flash suppression and muzzle rise compensation, 3P15 (1/2 x 28) and 3P10 (5/8 x 24) are both dedicated flash suppressors/sound suppressor mounts that support Plan B and Atlas adapters. 

3P15 is both a precision suppressor mount for Plan B and Atlas compatible sound suppressors and a superb flash suppressor. Their design philosophy regarding suppressor mounts is that in addition to their ability to mount the suppressors for which they're designed, they should be good flash suppressors, compensators, brake, etc. in their own right   3P15 is shorter and smaller in diameter than many suppressor mounts/flash suppressors, 3P15's length and diameter are defined by compatibility with Plan B and Atlas adapters.  Given these parameters, 3P15 flash suppression performance can go head to head with flash suppressors that are longer and larger.

3P15 had 3 revisions, 3P10 had 5 before they were happy with their performance. The width and depth of the flutes on the exterior of the prongs have different widths and depths, and were designed to both reduce weight, and give each prong a different mass so they don't conspire to work as a tuning fork. 

The internal grooves serve to improve gas expansion and cooling, but by themselves, they're not sufficient to make the device a better flash suppressor. 

3P15 has external 0.900 x 24 threads, compatible with sound suppressors with 0.900 x 24 threads (such as CGS and Plan B) and adapters such as Rearden's Atlas adapter.

Specifications:

• Length: 2.15"
• Weight: 2.4 oz.
• Internal threads: 1/2 x 28
• External threads: 0.900 x 24
• Wrench flats: 3/4"

Please NOTE:

• 3P15 has wrench flats for torquing it on the barrel.  Do not use a screwdriver and insert it into one of its ports to torque it.  With 30ft lbs of torque, using a rod or screw driver will cause damage to the muzzle device.
• Screw driver not included (but seriously, use a 3/4 wrench, armorer's wrench, or JMW, not a screw driver.)