... growth. 1, Material: PVC 2,color: black 3, The product includes base, wall, and screw. Its service life is over five ... years. 4, The base can prevent the main root from being coiled. 5, The wall is an alternation of convex and concave. Its ... provide the condition for air-cut. The screw is new style, practical, fixing firmly, removing easily and saving cost. rapid cultivating seedling ...