eCase via Amazon offers the Kmashi 3-in-1 Bike Headlight / 4,800mAh Power Bank / Bluetooth Speaker, model no. Arma K1, for $19.99. Coupon code "K3VLQIZG" cuts it to $16.99. Plus, Prime members receive free shipping. (Non-members can spend $49 or more to qualify for free shipping; otherwise, shipping costs $5.85.) That's tied with our mention from a month ago, $33 off, and the lowest total price we've seen. It lights up to 164 feet and features a Bluetooth range of up to 33 feet, built-in mic, waterproof design, and bike mount. Deal ends January 31.