This product can be anything. Set here a subscription service or a simple onetime payment product.
Create Other Product Prices
ZBilling allows you to set a price for a product for X days + Y months
Payment Type: Free, One Time payment and Recurrent.
Allow Signup: If this domain is available throw New Order Webpage.
Days: If recurrent, this field will be used to SUM next billing invoice date. Example: 15, Invoice will be generated every 15 days.
Months: If recurrent, this field will be used to SUM the next billing invoice date. Example: 6, invoice will be generated every 6 Months.
The values is in the currency that you define in the product.