Descriptions:
This is a DC Electromagnet 6V, 9V and 12V Push/Pull Suction type that is designed to operate in pushing and pulling mechines. This lock uses a solenoid which is magnetized by the process called electro magnetization. In this process a voltage is passed in a coil which induces  a magnetic field in a coil, there for pulling the metallic arm inside .
 
 Specifications 
Electromagnet size: 13*15*20 MM
Core diameter: 5 MM
Core length: 24 MM
Line length: about 160 MM
Weight: about 20 g
Resistance: 50 euro
Attraction: greater than 70 GF
Adaptive voltage: DC 6 V - 12 V (No information from the supplier, we estimate by testing.)
Voltage: DC 6 V current: 0.1 A
Voltage: DC 9 V current: 0.17 A
Voltage: DC 12 V current: 0.21 A