Review on Green Hanging Snap Hooks: BETOOLL Heavy Duty Swing Hangers For Wooden Sets, Playgrounds, Porches, Indoors, And Outdoors - 2400 Lb Capacity (2Pcs) by Jontrell Fernandes

This is a pretty great product! I do wish it came with instructions, but these ebay reviews were helpful enough. The box did include a sticker template with a predrill recommendation (5/16"), but after predrilling I had a lot of trouble getting the lag screws in with my entry-level drill + 3/4" socket attachment. My first instinct was that I needed to predrill a larger diameter hole, but then I realized that these screws need to support hundreds (theoretically thousands) of pounds. I found a few reviews confirming my suspicions, and then ran to the local store to get an impact driver, and after that it was a breeze!