Nova Tech US via Amazon offers the Nursal Rechargeable Tens Unit with 8 Pads for $35.99. Coupon code "QX9YPGFW" cuts the price to $25.99. With free shipping, that's the lowest price we could find by $15, although we saw it for $4 less three weeks ago. It features 16 modes, 20 strength levels, and a built-in timer from 10 to 60 minutes.