From the Manufactor
SKU: 1554 To find these little gems we tested more than 40 speakers and hands down these are the best small format speakers we have ever heard. Producing sounds with the clarity and volume of a much larger speaker these 20mm (0.79″) speakers are perfect for tight installations that still require BIG sound. This speaker has an adhesive ring around the front which can be used for mounting or ignored. 20mm (0.79″) diameter and 3.4mm (0.134″) thick