Fusion Engine R107 Solenoid Valve Shims & Spacers you can install a spacer

you can install a spacer in-between the rear of the engine and the receiver to push the engine forward when the buffer tube is tightened down

and with Monk Customs Oracles to achieve that "impossible" perfect alignment

It does not fit F2

Whether your Frankenstein project didn't go as planned or maybe you just stripped a screw

All UGS stocks for M4 models use the "Original" rails

Fusion Engine R107 Solenoid Valve Shims & Spacers you can install a spacerThe R107 is the solenoid valve used in all current production Fusion Engines and is backwards compatible with all production engines back to the GEN1. This valve is specifically made for the PolarStar Fusion Engine and has higher wattage coils and tighter seals than an off the shelf MAC 33A valve. Compatible with all versions and generations of the Fusion Engine. 4. 7 watt coils provide faster response and operation. Tighter seal squeeze for increased