The locking screw is at its best in guns that don’t have a separate buffer tube locking screw (like in AK series guns). The locking screw centers the spring guide, so it doesn’t move or vibrate.
The screw has been manufactured out of steel.
The screw is directly compatible with the following spring guides:
The spring is not compatible with ARESEFCS boxes, but by changing the spring guide you’re back in business.
RetroArms – CNC Engineering at Best
RetroArms is a Czech airsoft company which manufactures high-quality upgrade and spare parts. The company has become known from its CNC machined parts, especially its super durable gearboxes which are made from 7075 aluminum. RetroArms gives its gearboxes a lifelong guarantee against breaking which tells us a lot about the quality of the parts!