Apple Thunderbolt 3/USB-C to Thunderbolt 2 Adapter - Micro Center
Apple MMEL2AM/A Thunderbolt 3 USB-C to Thunderbolt 2 Adapter for sale online | eBay
StarTech.com TBT3TBTADAP Thunderbolt 3 to Thunderbolt 2 Adapter - Backward Compatible - USB C to Mini DisplayPort - USB-C to Thunderbolt 2 - Newegg.com