Heater for hummingbird feeders

Need an effective, lightweight way to keep hummingbird nectar thawed in the winter? Made in Washington State. Rated for outdoor use (no fire hazard). New version has non-slide rubber top. Comes with 7-watt bulb, and includes a FREE 15 watt bulb for use when your spot is exposed to colder weather or wind. Just pennies to operate. 6' cord. Fits most feeders with a bottom at least 4.25" wide. A weather guard above is recommended. Feeder not included. Fits onto any feeders with a flat bottom of at least 4.25" and perches to hook onto.  All sales final. SAVE ON SHIPPING - get a set of 2. Single heater usually ships for around $9.