Internal and external upgrades. Base gun is a Battle Machine with a Lonex hop up, G&G green bucking and nub, and a Madbull 6.03 inner barrel. It comes with a Burst Wizard set to a three round burst. Externally, I swapped the original rail system (which is also included) with a metal CQB version with suppressor to cover the longer inner. Includes three hi cap mags, iron sights, and grip. No problems with it, it's a nice gun. Selling because it's an extra that doesn't get enough use. I'm looking for the Elite Force H8R, G&G ARP9, Wolverine Gen 2 Inferno or Reaper. Message me for questions and check out my other items for sale. Thanks for looking!