4 In Soil BlockerPropagation system that virtually eliminates the use of plastic trays. This time honored system of soil compressors forms blocks for seed starting or rooting cuttings. Designed for smaller sized cubes to nest in next larger blocks for easy up potting and minimal root disturbance. Highest quality tools imported from England. Press a single, 4 inch cube with a 2 inch impression for up potting the medium sized block.