Hard  Akadama earth mineral soil like clay 70%, when it is wet, become red ball  and 
Kiryu 15%  and Pumice 15%.  Especially good shohin, mame bonsai,ready to use,  makes plants grow and retain water and nutrient,  good drainage, USPS large flat rate box priority 2-3days shipping 12"x12"x5.5".
Repackaged because of shape of original bag.
No.1 seller in US and Asia.
1 to 2 mm and various size& weight  due to the natural product from earth.

Product $30.00 + priority shipping $19.75