Maple Leaf tornado valve is special design for WE M4 sersie of GBB. the advantage of tornado valve can saving the gas, and working highly effieicncy on the velocity shooting each time. with Tornado valve you don't need to carry too many of GBB magazines. fitting one tornado valve equal two magazines and velocity of speed start dropping after 25 round but one punch of gas can shoot upto 60~70 rounds