This is a super miniature rotor motor with eccentric wheel.
General specification: 4.5 * 5 * 11 MM (with shell and an eccentric wheel)
Light motor specifications: 4*7.5 MM
Voltage: 1.5 V current: 0.04 A (stall is 0.04A)
Voltage: 3 V current: 0.09 A (stall is 0.09A)