Latest update from Thumpy with his posting at his blog of the short demo of the PolarStar AEG to HPA conversion gearbox. To learn more, click the link to his blog as he is very much on top of this... "Check out the WORKING PROTOTYPE for PolarStar's INNOVATIVE Mechbox Replacement Engine. The HPA Gearbox Engine is IN A GUN and testing has begun. SEE THE VIDEO and links to more of the FUTURE OF AIRSOFT??? You decide along with ALL THE NEWS at THUMPY'S 3-D HOUSE OF AIRSOFT."