Buck the gen III A with twin motors & a higher voltage (6) allows you to flow a little higher number showing you a balance differnce easier the Gen III We normally flowed 32-34 . But on a HIGH QUALITY AIR DAY We flowed 22-24. The NEW GEN III A 6-volt Is more sensitive to a difference on the twins. Also Boris Now offers A High Capacity 2500Mah LI Poly Battery VS the 1400Mah std battery But it adds a little to the price. GREAT PRODUCT!!! I would not go to the lake Without it.. If you are Racing TWINS........... the Newest features of the Latest Flow meter are High Capacity Battery & a increase of Voltage to increase the sensitivity of the meter.