My Garden Post Combination Large and Small Planters, Green Two my garden post exclusive planters made of durable UV resistant plastic Mounts firmly on std, 4" x 4" wood posts for railings, mailboxes, lamp posts and more Large planter-15"w x 9"t small planter-9 1/2w x 6" t Functional draining holes with plugs Not for use on vinyl posts measuring more than 31/2" x 31/2"