I have 7 Beck zappers. I was thinking that too. So was covering the bases well. Since using 2 zappers overnight my energy levels have wet way up. That is a definite. It may require 2 zappers both wrist-to-wrist and ankle-to-ankle to have good effect. I doubt the same wrist method is that effective. So anyone attempting to knock down hiv with a Beck zapper needs to get 2 of them and zap both ankle-to-ankle and wrist-to-wrist. That may be the better method. Energy levels are way up.