Zipdiz 50ft Zipline, Backyard Zipline Kit with 5.9ft Spring Brake and Seat, Zip Line Kits with 2 Tree Protectors, Zipline for Backyard with 1/4" Cable, Up to 350lb

While this is a good starter kit you will need to purchase more parts to make this overall safe. A spring brake is fairly important depending on your slope. Also, a seat is definitely needed depending on your height of install. In general this is a fair value when considering the cost of adding pieces relative to whole kits that include items like a spring brake etc. It's a blast and the kids love it (for now).

This was very easy to set up, though this is not a complete set. I didn't realize there was no seat or brake with this kit and I didn't feel like I could put this at much of an incline because of that. My kids are enjoying it as it is, but they have to give it some momentum to get it to go faster.