PRICES MAY VARY. Adjustable Planter Box Bracket - The window box brackets are with adjustable design for the top and bottom of the brackets. The top width can be freely adjusted to accommodate your railing from 2” to 7” width,while the base width can be adjusted from 6” to 12.5”.You could enjoy the freedom of personalizing your space without any compatibility concerns. Heavy Duty Material - The bracket is made of 3mm thick iron and powder coated black finishing to prevent fading and corrosion.Th Outdoor Flower Boxes, Railing Planter Boxes, Window Box Brackets, Large Planter Boxes, Deck Railing Planters, Long Planter, Shed Windows, Herb Garden Planter, Deck Planters