Grodan Gro-Block Improved GR4 Small with Hole, 3" x 3" x 2.5" - Case of 384 Select Rockwool Type:GR7.5 Medium w/ Hole, 4" x 4" x 3" - Case of 192 The Original tumbler is manufactured

The Original tumbler is manufactured with rugged

It is now ready for the worms

as heat and humidity don't build up as much with more open space for your plants to breathe

and efficient for all your extraction needs

Grodan Gro-Block Improved GR4 Small with Hole, 3" x 3" x 2.5" - Case of 384 Select Rockwool Type:GR7.5 Medium w/ Hole, 4" x 4" x 3" - Case of 192 The Original tumbler is manufacturedNew and improved stone wool substrate with advanced wetting technology from Grodan Introducing Grodan Gro Blocks Improved, a product specifically engineered to deliver real results for your crops, developed by plant scientists, researchers, and top growers. A core component of the "Precision Growing" philosophy, Grodan Gro Blocks Improved with Advanced Wetting Technology allow you to cultivate more uniform and high quality crops while using less water