Ok perhaps Jaff does want just Nitro Duck Reg...unlikely as it is advertised as the whole thing, Bottle and Reg that their adverts are for, and yes if the bottle threads are the same then of course you can put a Nitro Duck Reg on an HSE bottle (never said you couldn't) What I was saying (though I did think it was clear) is that the use of a Nitro Duck complete system in the UK is illegal due to the bottle used and branded by themselves (Nitro Duck) is a DOT bottle. All works out the same as speed gun scanners legal to sell, legal to own but use the product and you are breaking the law (bottle only not the reg). Smart Parts (not picking on you guys) sell HSE and DOT bottles but then their market is not just mainland UK so they have reason to sell both, other dealers have similar markets but it is buyer beware, go ahead buy a DOT bottle and try and get it filled, tested or use at a tourny or site in this country. Think on this too PMI do a product called "Pure Energy" a bottle and reg that is 5000psi but it is a DOT bottle only.