1. Aimcor Excel briquettes, manufactured by Applied Industrial Materials UK Limited, Newfield, County Durham, or manufactured by Oxbow Carbon & Minerals UK Limited, Windsor House, Cornwall Road, Harrogate, North Yorkshire, which—
(a)comprise petroleum coke (as to 60 to 75 per cent of the total weight), low volatile coal and reactive coke (as to 20 to 25 per cent of the total weight) and cold-setting resin binder (as to the remaining weight);
(b)were manufactured from those constituents by a process involving roll-pressing;
(c)are unmarked pillow-shaped briquettes;
(d)have an average weight of 73 grammes per briquette; and
(e)have a sulphur content not exceeding 2 per cent of the total weight.