This charming knitting pin is for people who knit the Portuguese style. With the Portuguese style you with knit with the yarn around your neck (which can sometimes irritate your neck) or by using a knitting pin. With the knitting pin you pin it up near your left shoulder and tension the yarn in the hook. I found this style of knitting due to an injury with my wrist where it hurt to much to knit English throwing style and I love this style of knitting so much better.
since you are using the pin as tension your hands stay on the needle which causes less hand movement which is easier on your hands. This style is very easy to learn, and you are also able to knit faster.
To use open the lever back and push through your shirt close and you are ready to knit.