An indispensable element, even if the feeling is sometimes a bit cool on the skin. It might sound weird like texture, but it is clear that it makes all the difference: it allows a better grip and thus greater efficiency of Compex. The electrodes are also easier to put on and remove, and freezing extends their lifespan.
Non-greasy gel, no sticky, fragrance, cleans easily. And the good point: it lasts VERY VERY VERY long time! A good investment, then!