We just picked up two Keter Adirondack chairs from Sam’s yesterday. They have to be assembled and have three screws on each side that we think we’ll coat with silicone to protect. They should probably be ok anyway since designed to be outside. The chairs are nice and heavy and shouldn’t float away once on the ledge. We looked at the $18 plastic adirondacks at Lowe’s, but these seem a bit sturdier. $79 at Sam’s Club.