STRETCH Sewing machine needles size 90/14 for stretch fabrics pack 5 needles by Schmetz

Stretch 90/14 sewing machine needles. The shank of this needle is flatter than on other needles with the same diameter. This means that the needle is closer to the hook, which helps to avoid skipped stitches.

Sewing machine needles by Schmetz are wellknown and of excellent quality.
Use stretch sewing machine needles for sewing woven stretch fabrics. For example a wool-polyester mix with a few percent elastan or lycra. Woven stretch fabrics are woven with a stretchy fiber. Not to be confused with met jersey, that is a knitted fabric for which we sell special Jersey needles. If the Jersey needle does not work for your knitted fabric because of the sewing machine skipping stitches, then use a stretch needle instead.
Suitable fabrics: woven stretch fabrics, swimwear fabrics, fine jersey, silk jersey, velour cloth, cotton knitwear. The higher the elasticity of the fabric, the more suitable the stretch needle is.
 

Is choosing difficult?
In this PDF we have explained the combination of fabric, threads and needles: 
Thread and needles user tabel

TIP: a needle kan work for 8 hours, afterward it is blunt and needs replacing.

That does not mean that you have to exchange the needle after one day. Look at it this way: if you should push the pedal and keep it sewing for 8 hours straight the needle is blunt 
Easiest way is to put a new needle in the machine when starting a new project...