Steel Hook

A steel hook is used for use with very fine threads/yarns (usually cotton, linen, silk, or fingering weight yarn.) Sizes range from 00 to 14 and the larger the number, the small the hook size. Length 5".
Regular Hook

Regular hooks are for working with lightweight to heavy weight yarns. These hooks are available in aluminum or plastic and are 5"-6" long. Sizes range from B(2) to K(11) and the larger the number, the larger the hook size.
Jumbo Hook

Jumbo hooks are the same as regular hooks only much large and usually made of wood. These hooks are used with very bulky yarns and available in sizes 10, 11, 13, 15, and 16.
Jiffy Hook

Jiffy hooks are made of hollow plastic and used with very heavy yarn or fabric strips. These hooks are 8" long and available in sizes Q and S.
Broomstick Lace Needle

A broomstick lace needle (also called a jiffy lace needle) is a knitting needle used with a crochet hook when making broomstick lace (also called jiffy lace.) Made of hollow plastic and this needle is available in sizes 17, 19, 35, or 50.
Double-Hook Needle (Also called Double-End Hook)

A double-hook needle also called a cro-hook is a special afghan hook used when making double-faced fabric in two colors. This 14" hook is available in sizes F to K plus M and N.
Afghan Hook

An afghan hook is used when working Tunisian crochet (also referred to as afghan stitch.) Tunisian crochet produces a knit-like fabric. This 9", 10", or 14" long hook is available in sizes E to K.
Flexible Afghan Hook

A flexible afghan hook is designed to hold a large number of stitches and is available in sizes E to K. This hook is a regular hook with a nylon extension attached.