If you’ve got a big enough yard, strong enough arms, and (optional) tough enough kids, Amazon’s running a sale on DIY zipline kits that will surely not end in any kind of injury. No sir, definitely not.
You’re looking at $130 for a 95' kit, $62 for a 60' kit, or $216 for a 120' kit with some extra accessories like a harness and gloves. All of them can support adults up to 250 pounds, so everyone can take part in this bad idea.
Just note that the 60' kit doesn’t include a brake like the larger ones, which seems like quite an omission.