EMG x Retro Arms CNC Machined Aluminum Hop-Up Unit for AK Series Airsoft AEGs (Color: EMG Black)

"The hop is indeed up on the particular device.

"This is a well-made, precisely machined hopup unit. It required no fitting, sanding, or dremeling of any kind to install into my LCT LCK104. The only thing I wasn't 100% satisfied with was that the screw that holds this hopup unit to the gearbox wouldn't thread all the way in. Not a big deal at all though as it's still held solidly in place, it just looks kinda funny. Just to be clear, this is solely an aesthetic issue, not a functional issue. I tried Prometheus Purple, G&G Green, and Madbull Blue hop up buckings. While they all fit, the Madbull was a substantially tighter fit than the rest, and I had to use some white lithium grease as a lubricant to ease the bucking into place. I recommend the Prometheus Purple and the G&G Green buckings as they slid in easier, while still providing a perfect air seal. I had no feeding issues using G&P AK74 mags and BLS biodegradable .32 gram bbs.

"This unit is literally the same as the regular retro arms unit. They are superb units, and the blue anodized one looks amazing. I bought it because I was in the market for a new hop up unit for my E&L ak 74 and this one happened to be the same color as my retro arms blue anodized aluminum trigger. This hopup requires no modification to fit into an E&L but will not fit a CYMA ak out of the box. I can't speak for LCT ak's. Overall the unit helped me hit 400 fps with less than a 2 fps margin of error in either direction with a G&G green bucking and angel custom 6.01mm inner barrel. As far as ak's go this is the best hopup you can get