... and not be decomposed or blow away. tree rings ,tree guards ,tree grates .materails : rubber mulch ,rubber buffingssize : 30"diameter x 1.0"30 ... 0.75"24" diameter x 0.59"rubber tree ring is made of recycled rubber, rubber buffings using compressed molding, installing it on ... the tree grow, becoming one as the nature. It suits different tree sizes and not be decomposed or blow away. rubber tree grating