The NOS brand remote opener is a solenoid opener. It sucks IMO. Its just s shuttle valve inline before the main feed line. There are still connections that could leak down between the bottle and the opener, not to mention the opener itself. That NOS valve also is quite restrictive and can only flow a medium amount of juice (maybe 250 shot). The NX,ZEX, Cold Fusion and others that mount to the top of the valve and physically turn the valve are better IMO. But they can be finicky and they require removal each time you want the bottle filled. So its a hassle as well.

I dont use an opener. I just ensure that all my nitrous lines are leak free by using a product called Snoop. do a google search for it. Its just fancy spray on leak detector but it works very well and will identify a very light leak. To fix leaky connections I use something called SECO seals. Its a dead soft aluminum flare gasket that goes over the male AN fitting. When I leave to go out for the night I turn the nitrous on and leave it on all night with no worry of leak down. Then purge and close the bottle at the end of the night. But if you must have a remote opener...the NX,Zex or others of that type are my personal preference.