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 HPA and M4 adapter for Tokyo Marui mags (L9B4K5UL5) by PrimaryAirsoft
Primary Airsoft - HI-CAPA WE TECH HPA/M4 ADAPTER - AirsoftJunkiez.com