T3 Terminator muzzle brakes are designed for .223 to 338 Magnums on barrels up to 25mm diameter.
The standard T3 threads are x 28, 9/16 x 24 & 28, 5/8 x 24, 28 & 32, M15, 16, 17, 18 x 1, 11/16 x 24, ¾ x 24 & 28
The T3 doesn t have a top or bottom, it has flats for a 23mm, 15/16 spanner and a small indexing mark so they can be easily fitted by the Gunsmith.
Ports are 90 degrees to the ground to reduce disturbance. The ports are angled back away from the shooter to minimise shooter discomfort and maximise performance.

The standard through holes are for .264 & .308
It requires opening up to 0.025-0.030 over calibre size when fitted to larger calibres.
It is recommended the rear of the brake be tapered down to the muzzle diameter.

The T3 is 25mm, 0.984  diameter, 69mm, 2.72  long & weighs 90-115 grams, 3.17-4.05 oz depending on thread.