Hey guys, most smoke pumps weigh 4 or more ounces plus an additional battery can bring the total weight up to 8oz or more. The harris pump will only add 2 oz + the wieght of the extra tank and lines so your total system weight is around 4 oz. The fluid does add extra weight but it gets pumped out during flight. You can do your aresti manuvers with smoke and when the smoke is gone the plane is lighter and you can finish off with 3D manuvers and such. Smoke adds a great apperiance to your airplane and flying skills that spectators love to see, especially with biplanes. I have smoke in a yak 54 and in a pitts python. For some reason the smoke in the pitts is more show stopping and appealing to the human eye. Customers from around the world have been using these units that plug directly into your receiver for many years,it is simple light and very low draw only 25-40 mah are used for 6 minutes of smoke. We have never had any reports of anyone having problems with the pump pluged into the RX. The pump draws less than most hi torque servos. rc3dflyr