AirsoftSquid demonstrate their Glock 18C Dual Recoil Spring Kit for the Tokyo Marui G18C GBB Pistol and other compatible G18C GBB pistols... "This kit aims to reduce recoil and with the dynamic spring rates means a more appropriate spread of resistance against the firing stroke. With that it should result in better accuracy, more speed, and less recoil.

According to them, a big issue with many G17 and G18 is that the stock spring allows the slide to move freely with very little, almost no pressure. This has resulted in cocking while holstering or handling for many people. With the quad spring kit, this does not happen.

There is less gas released through the blow-back system, which means more shots per refill and quicker return means quicker full-auto speed (rounds per second — RPS).

The Short stroke means that recoil is even quicker and RPS increased even further.  However, the empty-clip lock-back mechanism will no longer work. This means you can dry fire without any BBs remaining in the clip."