This kit along with the other internals kit, (plus other upgrades like, spring, o-rings, reinforced stock/grip, etc.) can turn a nexus pro into a heavy hitting dmr/sniper blaster.
Like others have said, the plunger tube and telescoping pusher tubes can be alittle annoying to seal. The worker plunger tube is slightly larger than stock, so the original plunger o-ring wont give a consistent seal. The best solutions I found after some trial and error was to just use slightly larger o-rings on the plunger and telescoping tubes with a thin layer of ptfe tape under the plunger o-ring. And a generous lubing with a good quality silicone grease like super lube. Then finally, after adding a blowout guard my nexus has been 100% consistent and reliable. For o-rings, get the metric and standard large o-ring assortments from Harbor Freight. With those 2 you'll probably be covered for any other future projects.