Mustad fish hooks are sized on two parallel systems. Bigger hook sizes are notated as a number, a slash, and a zero, with larger numbers indicating a larger hook. Conversely, smaller hook sizes are represented as a single number, with a smaller reference numbers equal to a larger hook. The largest overall hook the company manufactures, as of 2015, is a size 19/0 shark hook, while a size 32 hook is the smallest, suitable for fly fishing.
Mustad fish hooks are similar to other hooks in that they begin with the point, which may or may not have a barb. Beyond this, the hook turns into the bend, which connects to the shank of the piece. The straight-line length between the point and the shank is referred to as the gape, while the distance from the gape to the deepest part of the bend is the bite or throat of the hook. The shank of a hook terminates in the eye, where a fishing line is attached.
The Mustad lines of fishing hooks offer variations on each hook component. Eyes are available in eight forms, including looped, open or swivel. Shanks can be multiples of short or long. The wire of the hook is measured for strength and diameter, offered as Strong to 4 Extra Strong in the former and Fine to 5 Extra Fine in the latter. Points, as well, feature either a barbless design for easy catch-and-release or one of seven barbed varieties, including needle, short or kirbed.