This piston is nice. Beware though, it is too wide to fit in a VFC SCAR-H gearbox without modifying the piston. I had to shave out the groove between the rails on the piston to make it loose enough to slide. I also had to remove the second-to-last tooth to prevent pre-engagement.
Seems very durable
Requires modification to fit in a VFC SCAR-H gearbox.