A 1 lb (454 g) can.
Lyle's Black Treacle is made from cane molasses, inverted sugar, and Golden Syrup. It is a dark and intensely sweet syrup. A classic baking additive in England, it is usually used in dark moist cakes, toffees, and Christmas puddings. And it has brewing applications. With a lovibond of 100, it is usually used in dark English ales (like an Old Ale) and sometimes in stouts and porters.
Usage: See recipe instructions. Usual usage is between 1/4 to 1 lb per 5 gallons of beer.