These Needles fit BERNINA SERGER  

The SIZE of the Needles in this listing is:  #11-HAX1-SP  (Metric Size 75)

This is a special version of the 15x1 for stretch or elastic materials and tightly woven knits. It is made to higher standards, it has the snake's head shape due to a combination of a slightly bulged eye and a slightly reduced blade above the eye. The bulged eye opens a slightly larger space in the material and the thinner blade above the eye reduces contact between the material and the needle . This reduces needle heat-up and prevents skip stitches.