Good but needs some design inprovments
I purchased the Arc Ex collar in UK overall the collar has good technology and works. It could do with some design change though because of its hight and having two prongs in line it can twist sideways out of position on dogs neck and end up lying on side. I tried the comfort winged probe head but although it has four probes they are still close together so twisting still happens. Although it wouldn't work for small dogs it would be useful if a probe existed wider than width of unit. Think like a boat with outriggers so twisting cannot happen