comprise anthracite fines (as to approximately 84% of the total weight), petroleum coke (as to approximately 12% of the total weight) and starch as binder (as to the remaining weight);

were manufactured from those constituents by a process involving roll-pressing and heat treatment at about 240°C;

are unmarked ovoids;

have an average weight of 45 grams; and

have a sulphur content not exceeding 2% of the total weight.