Specifications:

4-inch European gauge, one electric charge

4-inch European gauge, two electricity and one charge

4-inch US gauge, one electricity, one charge

4-inch US gauge, two electricity and one charge

4 inch bare metal (without battery)

Single battery

6-inch European gauge, one electric charge

6-inch European gauge, two electricity and one charge

6-inch US gauge, one electricity, one charge

6-inch US gauge, two electricity and one charge

6 inch bare metal (without battery)