It is 18650 battery 2 cell spacer.
Radiating during high rate discharge.
Every spacer has slots on edge for connection.
Size Approx: 4*2*0.8cm/1.57"*0.79"*0.31"
Note: Due to the difference between different monitors, the picture may not reflect the actual color of the item.
1 x Battery Spacer 18650 Radiating Shell EV Pack Plastic Heat Holder Bracket