Lord33 hey budd you were right for my katana the 400 is better for vapor and i opened the air hole 1/16 and 1mm on the fill hole, that's actually less than 1mm of the existing fill hole and it rocks, oh!!! i also put a pre order for a MINI BAM by zen what do you think is it worth it for $200 even though i already placed an order in, just wanted your input since you love Zen's pv