I saw the original prop during SDCC,
and after taking a close look at the TDKR acrylic suit and gadget display, i saw the system for retaining the cartridge was what appeared to be
a pcb card socket on the cartridge and. The Card was hidden inside the gun.
Order today, ships today. 3415-0001 – 50 Position Female Connector Non Specified - Dual Edge Gold 0.100" (2.54mm) Gray from 3M. Pricing and Availability on millions of electronic components from Digi-Key Electronics.