I think this is a phaser.but I'm not sure.any info would be appreciated.
It was not exclusively the MACOs. It was on the show since the first episode. It is the EM-33 plasma pistol and was the predecessor to the smaller phase pistol that was introduced to to the crew in the first episode. Most of the crew still used the plasma pistol till Reed could get them certified to use the new phase pistol.That's a 'MACO pistol,' from "Enterprise."