Lathe Chuck that I have no idea

Hi Everyone. Got this chuck (See Pics) when I Brought a secondhand lathe. Not sure what it is, what it is used for or how to use it. Advice would be really appreciated.!

Hi, it is a Craft Supplies combination chuck, it was manufactured by Craft Supplies of Millersdale Derbyshire 30 - 40 years ago. Turn the jaws large face down and fit a strong elastic band over the smaller ring on the back then fiddle the small diameter through the ring of the knurled locking ring. The elastic band just helps to hold the 4 jaws in place. The jaws have a matching taper to the taper boss fitted in the chuck body, as you tighten the knurled ring it forces the jaws up the taper and expands the work holding jaws. To use the chuck slacken the locking ring so that the jaws are at their smallest diameter, carefully measure this diameter and make a note of it. With the workpiece held on a face plate or wood screw (le a bowl blank) turn the face flat and accurately mark the diameter record from measuring the jaw diameter then turn a recessto that diameter and about 5 mm deep and form a dovetail taper to match the taper on the jaws. Turn the underside shape for the bowl and sand to finish. Screw the chuck on to the lathe spindle now fit the bowl recess on to the jaws and tighten the ring expanding the jaws until they are tight, originally the chuck came with a C spanner which fits in the hole on the outer ring, make sure it is really tight before you start turning the inside of the bowl. The chuck did come with a range of attachments and does work but not as good as the modern day self centering chucks. Work safely and have fun.