[ARES G36C]

stuck a Prowin in my Star UMP & went from 300 to 350 fps, so expect an fps increase + better fps consistacey.

One more thing you must remove the top frontmost screw from the gearbox to get the hopup lush with gearbox.

Aleast I did with UMP.

[Ares Cheytac M200 - Review & Picture Thread]

order springs directly from PDI , thats what I did

In fact I order everything PDI from PDI home page.

[Ares Cheytac M200 - Review & Picture Thread]

AEG spring diameter = 15 mm

VSR-10 spring = 10 mm

Lylax APS spring = 12 mm

PDI SS 2000 , 3000 , 4000 , 5000 springs = 13 mm.

hope this helps

PDI VSR-10 springs = 11 mm

[Army Armament R85 (L85A1)]

As for adding a susat Armycode sells the mounting rail for that sight separately, check WGC ( mounts & rails )