holder battery li-ion 18650

this is a holder for batteries li-ion type 18650. This batteries are used with laptops, then have very good current 3500mAh and voltage of 4.2v, this make them excellent for little robots.
All that needed is:

• piece impresed.
• Bolt, washer and nut of 3 mm.
• Wires.
• spring 8 mm.

Regards. C|:D