61. Taybrite briquettes (otherwise known as Surefire briquettes), manufactured by Coal Products Limited at Immingham Briquetting Works, Immingham, North East Lincolnshire, which—
(a)comprise anthracite (as to approximately 60 to 80% of the total weight), petroleum coke (as to approximately 10 to 30% of the total weight) and a molasses and phosphoric acid binder (as to the remaining weight);
(b)were manufactured from those constituents by a process involving roll-pressing and heat treatment at about 300°C;
(c)are pillow-shaped briquettes marked with a single indented line running longitudinally along each face, offset from its counterpart by 10 millimetres, or unmarked;
(d)have an average weight of 80 grams; and
(e)have a sulphur content not exceeding 2% of the total weight.