It will hold securely four or more chairs (depending on chair style) or a couple bikes on most standard 1 inch and 7/8 inch diameter ladders that include adapters. A rolled up outdoor mat or rug will easily lash to the top as well.
It has glass-filled nylon construction with UV protectants and zinc-plated hardware. This rack is lockable and won’t rust or corrode, and it swings out of the way quickly for ladder access — a feature most laddder racks don’t have. It also includes an adjustable strap to stabilize chairs while traveling.
You can find it on Amazon for less than $30 with free shipping.