Interested in a CRBN Upper, but not sure which one is right for you? You're not alone. With multiple styles, colors, and lengths, it's easy to get overwhelmed.

In this guide, we hope to help you make a better decision on what upper you should buy!

What are the two types of CRBN Uppers?

The CRBN AEG Upper (Left) and the CRBN HPA Upper (Right)

Both come with fiber optic sights, a genuine carbon fiber tube, and dual hopup windows. However, the distinguishing difference is that the HPA upper can only be used with HPA rifles while the AEG upper works for both HPA and AEG rifles.

The HPA upper also requires the CRBN gearbox to use a drop-in engine like the Polarstar F2 or Jack. The AEG Upper works with nearly every gearbox, only requiring a small dremel modification to remove the nub on top.

Both also come in 7 colors: Matte Black, Gloss Black, Red, Blue, Purple, Silver, and Gold. These are purely personal preference, pick whichever color you like!

The final thing to consider is barrel length. Depending on how long you like your barrel, you can choose from a 128mm, 155mm, and 185mm versions, which refers to the inner barrel that upper is compatible with. The 128mm is the shortest and most agile, but is more difficult to reach high FPS. The 185mm is longer and provides the best accuracy and FPS, but is a little harder to maneuver.

With these 3 considerations, you should have all the information you need to choose your perfect upper and get to building!