The following product description and guide are from ORGAN:
TWIN STRETCH 130/705H [FOR KNITS]
This needle is suitable for sewing stretch material like knit and sportswear fabrics and for creating decorative stitches. This needle has a special designed shape and medium ballpoint for better loop formation, thus preventing skipped stitches and fabric yarn breakage.
Basic Needle Knowledge
Sewing machine needles should be replaced regularly, because worn out needles can cause damage to delicate fabrics.
Blunt or bent needles will produce skipped stitches and thread breakages.
In extreme cases, the usage of worn out needles can result in damages of the stitching plate and surrounding parts.
After use, we recommend to put the needles back into the original boxes. This is a good place for keeping them and mismatching with other needles and sizes is excluded (prevented).
When is it time to change your needle?
After every 3 full bobbins used or every 2 pre-wound bobbins used. A tell-tale sign that the needle needs to be changed, is when the sewing machine makes a thud or popping sound each time the needle comes into contact with the fabric. This is an indication that the needle is blunt; it is unable to pierce the fabric smoothly.
Or just keep it simple and start with a fresh needle with each project!