Proozy offers the LifeStraw Personal Water Filter, model no. LSPHF017, for $19.99. Coupon code "WATER" knocks that to $13.99. With free shipping, that's a buck under our mention from three days ago and tied as the lowest total price we've seen. (It's the best deal now by $2.) This award-winning, BPA-free device enables you to safely drink contaminated water.