Vr6 Auto Question

[Antihero1981 8]

Does anybody know what the item sitting on the auto gearbox is for? it has pipes coming into it from the cooling system.

I replaced my hoses yesterday but the samcos did not have an outlet to join up to this so i have just left it off

i will try and get a pic later buts its very close to the outlet and inlet water pipes on the engine for the rad

thanks