Newegg offers the Rosewill 150-watt Noise-Free Power Inverter, model no. RCP-E150C, for $19.99. Coupon code "EMCYTZG788" cuts the price to $13.99. With free shipping, that's a buck below our September mention and the lowest total price we could find by $9. It features a USB port and LED indicator. Deal ends July 29.