1)The cable was never used, but there might be little scratches or dirty marks.
2)this is Thunderbolt 3 to Thunderbolt 2 adapter, it does not work with any USB-C devices or Mini Displayport devices.
3)The adapter doesNOTduplicate the functionality of the Thunderbolt ports on MacBook Airs and legacy MacBook Pros when daisy-chaining accessories together.

Descriptions:

The Thunderbolt 3 (USB-C) to Thunderbolt 2 Adapter connects a Mac that has a Thunderbolt 3 port to a device that uses a Thunderbolt or Thunderbolt 2 cable.

Note:

This adapter is not compatible with USB-C ports that don't support Thunderbolt 3, such as USB-C hubs or the USB-C port on MacBook models from 2015 or later.

Video

Use the Thunderbolt port of this adapter to connect your Mac to a display that uses a Thunderbolt or Thunderbolt 2 cable. For example, you can use this adapter to connect your Mac to an Apple Thunderbolt Display or LG Thunderbolt 2 display.

This adapter is not compatible with displays that use DisplayPort or Mini DisplayPort, such as the Apple LED Cinema Display. Thunderbolt and Thunderbolt 2 are not the same as Mini DisplayPort, though the ports have the same shape.

Data transfer

You can also use the Thunderbolt port of this adapter to connect an external hard drive, dock, Mac, or other device that uses a Thunderbolt or Thunderbolt 2 cable for data transfer. This adapter supports data-transfer speeds up to 10Gbps with Thunderbolt devices, and up to 20Gbps with Thunderbolt 2 devices.

This adapter is offerirectional, which means you can use it to connect Thunderbolt 3 devices to a Mac that has a Thunderbolt or Thunderbolt 2 port. In that case, the Mac must be using macOS Sierra or later, and the device using Thunderbolt 3 must provide its own power.

• The Thunderbolt 3 (USB-C) to Thunderbolt 2 adapter lets you connect Thunderbolt and Thunderbolt 2 devices — external hard drives and Thunderbolt displays, for example — to any of the Thunderbolt 3 (USB-C) ports on your MacBook Pro.
• As a offerirectional adapter, it can also connect new Thunderbolt 3 devices to a mac with a Thunderbolt or Thunderbolt 2 port.
• In addition, it can be used to connect Thunderbolt-enabled displays — such as the Apple Thunderbolt Display and LG Thunderbolt 2 displays — to any of the Thunderbolt 3 (USB-C) ports on your MacBook Pro. However, using this adapter with an Apple Thunderbolt Display requires a power source, because th
• Note: This adapter does not support DisplayPort displays like the Apple LED Cinema Display or third-party DisplayPort and Mini DisplayPort displays.
• Compatible with iPad mini, iPad Pro, MacBook Air, MacBook Pro, iMac, Mac Pro and Mac mini with thunderbolt ports