Hello. We offer services. I an trying to set up a SKU that is BUY 4 items, get one Free. I want to set a single SKU which contains 4 quantities within that SKU. I don’t want the customer to have to select 5 x quantities to receive a discount. I am essentially trying to issue volume credits within a SKU. Class pass is the best model I can think of. You buy a package and get issued a certain number of credits to use on classes. When you run out of credits, you have to buy another package. I want a single SKU that gives a customer X number of services. I need to be able to track how many services they have used. Can anyone recommend the best app or method of doing this?