Luis of 4UAD Smart Airsoft explores an aftermarket bullpup conversion kit, the SRU SARB15, which is used to transform a Double Eagle BRN 180 gas blowback airsoft rifle. Because the original rifle utilizes a short-stroke piston system that does not require a buffer tube, it serves as an ideal candidate for this compact redesign. The modification effectively relocates the firearm's action behind the trigger, drastically shortening the total length of the rifle while retaining its original barrel length.

In this 4UAD Smart Airsoft ASMR video, Shou takes a look at two products: the Double Eagle BRN180 gas blowback rifle and the SRU SARB15 Kit. He begins by unboxing both packages, walking viewers through the contents of each before moving into the build process.

Jeidanten's video demonstrates the installation of the SRU SARB 15 AR-15 M4 GBB bullpup kit. This airsoft kit, designed for Mil-Spec GBB AR-15 lower receivers, features a 15.3-inch length of pull and a total length ranging from 26 to 29 inches with a 16-inch barrel. The kit itself measures 20 inches without a handguard and 25 inches with one.