[Plugin: WooCommerece] Check box to add additional item

I am selling a few different items, one of the items is a polishing cloth for $3.00 and different pairs of earrings. If someone goes to buy a pair of earrings I want to have a check box to allow the user to simultaneously add a polishing cloth for a discounted price of $2.00 if they choose. Any ideas on how to do this?

Thank you for any information you might have