This is the Exxentric kPulley Go: a portable strength training tool that uses a flywheel for variable resistance. It can be used indoors and outside. Simply attach it to a squat rack or post, and you are set. This set comes with kGrips, ankle cuffs, and everything you need to get started but you can buy more accessories.
The kPulley Go can hold up to 2 flywheels. It weighs only 9.5lbs, so you can easily take it around. The drive belt measures 59 inches. You can find out more about it here.