RedRock Starter Block PRO, 4" x 4" x 4" (Case of 144)RedRock Starter Block PRO, 4" x 4" x 4" (Case of 144) Dimensions: 42 40 Hole 10x10x10cm 4 Inch x 4 Inch x 4 Inch Commercial grade stone wool pro starter blocks sourced and manufactured in North America. Our Stone wool is made in the USA Wetting agent ensures nutrients are immediately plant available The high fiber density of the stone wool starter blocks makes better use of water and fertilizers while allowing dry back Our stone wool starter blocks