I know a lot of people hate the Primary Airsoft adapters, but when it's 110° outside, a light kit is a life saver. Also a great first step into HPA : r/airsoft
Hi Capa - Which / How to HPA? - Mag Tap & Primary Adapter - YouTube
Tokyo Marui Hi-Capa Pistol HPA Drum Mag - YouTube
HPA adapter M4 charger for Hi-Capa series
CUSTOM HI-CAPA HPA DRUM MAG | RICO - Team Member Edit | Airsoft at Running The Target Den Haag - YouTube
STL file HI-CAPA to M4 HPA ADAPTER 🔫・Design to download and 3D print・Cults
STL file HiCapa to M4 - HPA Adapter 🔫・3D printing model to download・Cults
Protek "Pulse" HPA M4 Mag Adapter for Hi Capa – MasterShot Custom
Amazon.com : SS AIRSOFT Primary Airsoft HPA/M4 Adapter | Hi Capa Airsoft Adapter (Tokyo Marui, WE Tech/Armorer Works & Novristsch/KJ Works) : Sports & Outdoors