These are micro-switches that are meant to replace the stock switch in certain electronic paintball markers. They should fit all Spyder and Dragun eclectronic markers.
These will lessen the trigger force required to fire your marker. This usually results in faster walking. These are not like the 50gs you see with levers. A lever lightens your pull, by increasing the pull length. This is an annoyance, so most consumers remove the lever. Unfortuanately, that results in a pull that is around 250gs, just like your stock switch. These have no lever, and are not sloppy feeling like lever switches. The trigger can be activated with less than 1mm of finger movement, provided your trigger is adjustable.
This is one of the cheapest, easiest, and most beneficial upgrades you can do to your markers.