I've only just begun exploring elctro, as a first unit that's affordable and comes with 4 pads and connector cable, I could not be happier. I won't "do" to someone what I haven't already done to myself and this unit is allowing me to experiment, discover and gain a finer appreciation for the kinkier things in life especially with Electricity! (I know, it's the 21st Century already, why haven't I got a full body compression suit that's wired up and will give me just the right stimulus throughout the day to keep me "fresh"....but I digress.) Only gets 3 stars which is no reflection upon S(A)X - customer service I received was exceptional and the item arrived in good time even under the current circumstances. (No chicken little running around screaming the sky is falling, but you never know what The Orange One will pull.) My dissatisfaction is with Zeus themselves. When I opened the parcel, everything was there, except a warranty card or an instruction manual (I don't expect a warranty on something this inexpensive), but instructions...ooops, missed the website, no problem, log in, navigate...beautiful photography but no sign of an operating manual. An experienced friend has given me help in the meantime, and I expect that a simple interface wouldn't require instructions; until you find out how many variables 4 buttons and a cheap LCD screen with small graphics and non-universal symbolic language - the nifty pics that someone with 20 years of free clipart decided to add which "presented" the unit but offered no real indiscombobulation (it's a new word, just added a prefix, take it or leave it...lol) or indeed confidence that the unit could be used safely. 2 1.5 volt AAA cells wouldn't give anyone a heart attack...but I did get quite a shock when I was placing 2 of the pads and contacted from one patch with one hand while using the other hand to site the other 2 pads, contacted and gave myself a little neck cramp - took 15 minutes of my husband's expert massage technique to unlock, but I'm pragmatic, nothing ventured, nothing gained so I accept a certain level of risk.

Is the one thing that this device suffers from. 2 Lithium AAA batteries should give up to a couple of hours of fun, rechargable NiCads only last 20 - 25 minutes (lower specific power density, lower overall voltage/wattage)