This system of extending crop cages is very simple to install. Additional cages can be added or removed. Three types of netting can be used bird, butterfly or insect net. This crop cage system is especially useful for protecting plants from butterflies laying their eggs on the plant resulting in decimation of the leaves in late summer. Self-assembly required. All tubes have an outer diameter of 13mm & inner diameter of 11mm. 10 year guarantee. Netting not included. 1m tubing x 4.