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
HPA adapter M4 charger for Hi-Capa series
Hi-Capa M4 HPA Adapter Lower by captaINstraiTJacket | Download free STL model | Printables.com
Poseidon HPA Series Stormbreaka GBB M4 Adapter for G Model / Hi-Capa GBBP ( HPA Only )
ShadoWorkz | Quezon City
TAPP Airsoft Modular M4 Magazine Adapter for Gas Powered Airsoft Guns (Model: Timberwolf / SAI BLU / ISSC M22), Accessories & Parts, Airsoft Gun Magazines, Gas Gun Magazines, M4 / M16 -
Primary Airsoft HI CAPA HPA / M4 Adapter for Tokyo Marui Magazine - Airsoft Extreme