Airsoftjunkiez are taking pre-orders of the Redline Airsoft N7 HPA Drop-In Kit for M4 AEGs and here is their review... "The N7 is not just another cylinder replacement engine. It uses a single solenoid, and is designed to replace an AEGs compression cylinder, but that’s where the similarities end. The N7 is a truly unique design.

Here is an overview of the latest offering in HPA Airsoft, the RedLine N7 HPA Drop-in Kit, as done by Amped Airsoft... "Anthony is in the Amped studio today to give you guys a quick look at the brand new HPA offering from Redline Airsoft: The Redline N7, a true nozzle-forward biased system that may look like the other offerings on the market currently, but the function is quite different.