TENS (Transcutaneous electrical nerve stimulation) massagers seem a bit like pseudoscience, but every time we post a deal on one of these things, we hear nothing but rave reviews. In fact, I use one occasionally after exercising, and it does seem to reduce muscle pain. At the very least, it feels cool.
This model from Auvon includes 20 modes and eight reusable pads (in two different sizes), far more than you’d get from most competitors. Just use promo code F7J74KMH at checkout to get it for $25.