Heavy duty,
The best things to send him is hygiene items..Try baby wipes, shampoo, waterless shampoo, deoderant, etc. Also on slow moments it can be boring so a few magazines to read just pick a topic that you think he may like. Hand held battery operated games like poker, etc. A deck of cards....Food items are good also. Cans of tuna, beef jerky,a can of nuts, anything that will not go bad with shipping or the weather there.
My mother often sends out packages to people and these are some items not only she sent out but also people I know whos hubbies are out there.