Over several decades, a number of edition of the Crawford Collets application booklet were published, this being one of the last.
The very useful and versatile Crawford "Multibore" collets that could each be adjusted to accept and range of diameters are covered here and the various Multibore collet chucks and collet holders of all types and sizes are shown and listed here
The writer would like to add further editions, these containing details of collets used on obsolete machines. If any reader can help with older copies, the writer would be delighted to hear from you.