Small pump-action water weapons had their day in the past, but with air and now CPS (i.e. rubber) based water-pressure weaponry out there, pump action weapons would definitely take a beating in the field. However, unrealized by many until it was made clear, the newer weapons just did not act as a good indoor weapon. The fact is firing a CPS 2500 indoors is not a good thought unless one really does not care about furniture, walls, carpetting, etc. Indoor urban water warfare became basically unthought of unless one planned on growing mildew over most pieces of furniture due to the deluge of water thrown on everything.
Perhaps it is this niche that Larami Ltd. has tried to corner in the market as well by making these mini-XP collector series. These weapons would not be able to make it against even a weapon as small as an XP 20, but indoors they provide a safe amount of water in the reservoir, a not-too-much-water rate of fire, concealability plus a range which is rather impressive for such a small weapon. The water yield from these weapons is much greater than that of the Super Soaker® keychains, but not to the point of drenching anyone on contact. In fact, the amount of water delivered is just enough to be annoying while not enough to leave any permanent wet marks.
In the end, these mini-XPs are perfect for small skirmishes indoors where one does not want to get soaked but does not mind getting a little damp.