Heineken Beer Bottle Christmas Tree Lights.  These are official from Heineken, they were part of a Christmas promotion here in Canada.  String is approx. 12 foot in length with 10 bottle lights, each spaced approx. a foot apart.  Each bottle is approx. 3-5/8" tall.  Powered by 2 x AA batteries.  If you're good with electronics, it wouldn't be hard to add a 3V DC power adapter.  These are new/unused and are in good condition with some subtle wear from shuffling in the box.  They have been tested and are in working order.  Please see photos for more details.