Is this DOT 4 fluid or DOT 5.1?! I've looked on a bunch of sites but can't see any mentioning it!! I'm fitting brake lines as soon as i get a chance so am after some high quality DOT 4 fluid, can anyone suggest any if the castrol one isn't? Also i'm in basingstoke and would prefer to pick it up in person but have know idea of what shops, within half hour drive, might have it. Any suggestions? Thanks