Mr. Garden 4ftx4ft Grid Kit for Raised Bed, Square Foot Garden, Sturdier, Easier 6 flat bars and 9 sets of push-buttons Material: Fiberglass, sturdier, more durable, use for long time Get your garden organized quickly, make your garden easier to maintain Super easy to assemble and use in your garden Easy to setup a raised bed garden anywhere. Makes it handy to maintain.Will not rot like wood and is made from recycled material