Garden Accessory Seed Starting Soil Block Maker Propagation Tray 5 per Order by David's Garden Seeds
The Soil Block Propagation Flat is the best 1020 poly flat system for your soil blocks.  It easily holds all sizes of soil blocks, from 3/4"-4", while maintaining air flow and air root pruning.  These trays are made by McConkey Plastics, and their formula has been upgraded, making these new trays stronger, more durable and quite flexible to hold heavy soil blocks without cracking or breaking and less fading in the UV rays of the sun.