The U.S. Postal Service (USPS) has expanded its electronic waste recycling program.

The Washington-based post office said in a news release it has expanded the program to 3,100 retail locations where customers can trade in their old electronic products for cash.

The Postal Service is working with MaxBack, an electronics recycling company that specializes in recycling unwanted electronics or buying them back. The USPS adds that shipping is free.

The USPS has a website, www.usps.com/ship/recycle-through-usps.htm, where consumers can search for their electronic device, receive a quote and mail the product. Once MaxBack receives the item, they’ll inspect it and send cash in return.

Even if the product has no refund value, free recycling mail-back envelopes are available for customers from participating USPS locations to ship their small used electronics, such as cell phones, smart phones, MP3 players, digital cameras or used ink jet cartridges.

Cell phones and electronics that are damaged and unusable are remanufactured or recycled by MaxBack’s parent company, Erie, Pa.-based Environmental Reclamation Services, a zero-landfill, reverse-logistics company.