Grow healthier seed start root system using the power of air pruning. Each cell has strips to allow wind / air to keep the roots from circling Build with food safety and longevity in mind. We only use Prime FDA grade Heavy Duty Polyproplene plastic. Engineered to last the life of the grower. Easy bottom watering in Bootstrap Farmers Extra Strength 1020 Trays. Dimensions - 19-13/16" x 9-14/16" x 2-5/16". Easily remove seed starts without disturbing the delicate root system with an Extra Large 0.87" bottom drain hole We proudly make this in the USA using ALL USA sourced materials. Nothing from overseas goes into this product