The AABB HR style carbine kit is one of the most economical options for Model 17 series gas blow back carbines on the Airsoft market. It is essentially a single piece polymer frame that fits over the top of a KSC Model 17 / 18C to add a solid stock and accessory rails all for the sake of increased tactical potential for enhance user options.
The stock features ergonomic grip pads for cheek weld and butt plate positions to enhance grip and comfort. An extended spring-loaded internal bolt sits against the pistols slide, a bolt handle can be attached from the left or right so that the slide can be cocked through the frame more easily. The kit also includes an option add-on plate on the side with a loop for affixing slings similarly to the metal ring on the end of the butt stock hook which can also be used as a sling mount.
The long top rail and shorter side and bottom rails are removable although removing the top rail of course removes any option of aiming optics at all. The top rail can be used to mount any rail attach optics of your choice, side rails can be attached to accommodate such modules as flashlight or laser modules and the bottom rail of course can be used to mount vertical grips or other less conventional options like miniature grenade launchers.
Do note that this is just a body kit and need the separate purchase of a KSC Model 17 gas blow back model 17 or 18c to be a complete weapon. This kit is available in both black and dark earth color schemes.
Last two images show demonstration example of a complete kit and pistol with added scope.