Convert your SSP18 or other Glock-based GBB pistol into an HPA-powered airsoft gun and use M4 magazines for higher capacity thanks to these adapters from TAIHENG.
Recommended with 0,20g ? 0,28g BBs and 80-120 psi air pressure. Do not use it with higher pressures!

Novritsch HPA M4 Magazine Adapter for Glock GBB

• Fiber-reinforced nylon (adapter) and zinc alloy (magazine) Construction
• No cooldowns.
• BB latching system to prevent dropping BBs after removing the magazine. It can be released by pressing the latch.
• Injection molded for durability.
• Adapters come with a US-Spec Connector.
• Made and designed in Taiwan by Taiheng.
  
• Suitable For Novritsch SSP18 Series Gas Airsoft Pistols
  
• Also fit for Most Umarex (Elite Force) Glock Series Gas Airsoft Pistols (Except GHK and VFC G42)
  
• Convert to use Most M4 AEG Rifle