This is insect-rearing mat made by finely crushing and fermenting the decaying wood of broadleaf trees like oak, used for raising beetles and stag beetles (for larval food, egg-laying substrate, and adult bedding). Brand new, unused. Approximately 10 liters x 4, totaling 40 liters. As a bonus, I will also send unopened oak mat and insect jelly (18 pieces). Please let me know if you don't need them.