Much More Battery Heat sink II
 

For Sale black much more battery heat sink II, Boxed in good condition. £25 inc pnp ONO

Specs from much more site below

Provides even heat dissipation of each cell, resulting in balanced temperature of the pack when charged or discharged under hot weather conditions.
Tight fit for sub-C size battery, providing maximum contact to the surface.
Striking anodized aluminum case.
Connectable to Cell master charger or DC12V.
High Quality 6 x cooling fans.
One touch handle secures battery.