It's alright but the large Stinger unit I have had for several years seems to zap more insects. The Stinger unit has a single 40W bulb that has a deeper purple color. I plan on switching the bulbs if the Stinger bulb fits the Flowtron and then compare results. Also the Stinger has a photocell that turns it on at dusk and off at dawn. The Flowtron stays on 24/7 unless you turn it off manually or hook a timer to it.