The Yankee Hill Machine Phantom is based on the Smith Vortex, but with a closed end.
There is the original 4 slot version with teeth and the newer 5 slot version, with or without teeth.
The 5 slot version without teeth is sold as the, smooth" version and is less likely to snag upholstery, clothing or seat belts.
The Phantom is as thick as an A2, so it's sightly heavier, but VG6 makes the 556 Delta, which is a similar length, but made of slightly thinner, hardened stainless steel, that is black nitrided and includes a crush washer.
The VG6 556 Delta often goes on sale for around $30.
The VG6 is sold as a compensator and is supposed to direct the muzzle blast forward.
It is much more of a flash hider than a compensator and better at flash hiding than the A2 and nearly s good as the YHM Phantom.
It has closed bottom and some blast does go forward out of its slots, but I don't know if that is by design or just the blast heading that way out anyway.
YHM Phantom or 556 Delta or maybe, an extended A2, or for open prongs, there are several other options.
YHM machine also has a compensator with nearly the same part number that doesn't suppress any flash at all, so make sure to choose the flash hider version.
The 556 Delta is sold as a comp, but it is in every way a flash hider.