These are designed to fit a number of Leica microscopes and are made for 220v (has a European plug) but works on 110VAC with the European to American adapter that we will include. Labeled as 240v 25W 50/60 Hz. Measures 7-1/2" x 4-7/8" with 64" cord and on/off switch. Get creative and build projects around them. Unused!