For propagating your own seedlings. 7 rockwool cubes (1 row).
Sized for the Tower Garden incubating starter kit for germinating seedlings before going into the Tower Garden.
To order 98 cubes ($11.95 plus shipping) from Tower Garden, click here.
To order a case of rockwool/30 sheets of 98 cubes ($199.00 plus shipping) from Tower Garden, click here.
You can learn all about starting your own seeds here: How to Grow Strong, Healthy Seedlings in 7 Steps
So what is Rockwool? Check out this article from Just4Growers!