What's in the box:

Andoer Brand New Upgraded Macro Extension Tube Set 3-Piece 13mm+21mm+31mm Auto Focus Extension Tube Rings for Canon EOS Camera Body and Lens of The 35mm SLR for Canon all EF and EF-S Lenses (Standard)

Features:
This is used by attaching between camera body and lens of the 35mm single-lens reflex camera. Compatible for Canon all EF and EF-S lenses.
It comes as a set of 3 tubes with different lengths (13mm, 21mm, 31mm) which singly or in combination makes it usable in 7 different lengths.
It couples perfectly with the camera's automatic diaphragm.
With camera of TTL, AE (Through-the-Lens, Automatic Exposure) type, it gives perfect coupling except when combined with electronic flash AE unit.
Upgraded circuitry and gold-plated electronic contacts to greatly improve signal sensitivity for working better with DSLR cameras and compatible lenses
Superior lock pin which can tighten the tube joint.
Exceptionally useful for macro photography, enabling you to convert almost any lens into a macro lens at a fraction of the cost while maintaining its original optical quality.

Specifications:
Brand: Andoer
Color: Black with red circle
Material: Aluminum alloy and PC
Tube Diameter: Approx. 62mm
Tube Length: 13mm, 21mm, 31mm
Item Weight: 116g / 4.1oz
Package Size: 10 * 7.8 * 7.7cm / 3.9 * 3.1 * 3in
Package Weight: 171g / 6oz

Package List:
1 * Andoer Macro Extension Tube Set (13mm+21mm+31mm)
1 * Storage Pouch
1 * User Manual (English)

Note:
Camera and camera lens are not included.