We have a vaccination certificate plan here right now so if you're interested in making an appointment to view my collection I will need a COVID checklist plus a survey which I will send out shortly
I don't know what you mean by "best" but this is easiest rechargeable option to power up a genuine Surefire P60 bulb in genuine Surefire 6P flashlight.
HO-4 is not a P60 and there are better options than 16650 such as 18650 or 26650