Amazon offers Prime members the Trademark Home Bright 7-LED Motion Sensor Entry Light, model no. 82-5293, for $17.46 with free shipping. (Non-members can spend $49 or more to qualify for free shipping; otherwise, shipping costs $6.94.) That's the lowest total price we could find by $4. It measures approximately 2.5" x 4" x 11" and uses three C batteries (not included).