The shape and strength of the cylindrical seedling is greatly improved and is more stable Rockwool block retains moisture and provides good aeration to promote healthy root growth. The Earthless Culture Block is an excellent choice for improving Earthless Culture homogeneity Turns molten rock into fibers like candy, which are then pressed into blocks. improved homogeneity and better stability and flexibility it is the best choice to achieve an even seeding effect Size: 20*27mm Package quantity: 50 pieces