This is a pair of clips that can fit almost anywhere. Made of light but sturdy plastic, the spring is strong enough to stay in place, but gentle enough to be comfortable on even the most sensitive areas, with soft rubber conductive pads on the tips. They are 9mm (0.4in) wide by 40mm (1.6 in) long. Any 2mm pin will plug into the top jack.
One set of two clamps works on one circuit/channel, each clamp is unipolar, so use with caution above the waist! It is best to split the channel, pair each clamp with a nearby electrode pad and not send current across the chest.
Also available with 2.5mm plug.