Beaver Plastics Hortiblock 242 Cultivation Tray- 1 pack Proven and accepted in a wide variety of commercial growing environments Allows growers to utilize and customize their own media economically and from local sources Made of rigid strong and lightweight food-grade material with mirror-smooth interior surfaces reduce root penetration while helping to promote plant development and higher yields Increased insulation of roots may reduce heating and cooling requirements helping lower overall production costs Easy to use handle clean sterilize and maintain