I use nothing but 1.25 ohm dual coils. I have a 1100mAh 3.7+ volt SLB kGo. My son uses 1.5 ohm and 1.25 ohm on his RIVA. No problems from either. They give awesome TH and plumes of vapor. The flavor is not as good as some methods, but with the right juice, it is great. Some ppl say they can't tell one flavor from a similar flavor with dual coils. Huh, smokers!