Tasco's Contact Information is here

Thier website didnt have an information on scopes that old that i could see. however if you contact them im sure they would know what size the battery needs to be, and would be happy to refer you to a place to purchase them (if not a product they themselves supply)

NOTE Tasco is a European company residing in Spain Madrid. You may be asked to send it overseas to be identified? (worst case scenario) if this is the case be sure to purchase a number of batteries for the device to make it somewhat cost effective

:) (I couldnt find the battery type as i dont know exactly what scope you have :(

Brad