Pushbutton feature
8mm rolling ball can be illuminated by LEDs
Electromechanical -- not sure what kind of internal mechanism they are
using
Assembly fits into a 9.5mm surface hole
Mouser sells 'em:
http://www.mouser.com/search/ProductDetail.aspx?R=TBWB2A00virtualkey61170000virtualkey611-TBWB2A00