If you are developing your Seeknit Interchangeable Circular Knitting Needle collection you may want to add a Converter to your toolbox. A cord converter can alter the fit between needle tips and a cords to make them easier to mix and match. Seeknit cords come in three different sizes: Size M1.8 cords work with needle tips 2-3.25mm, size M2 cords with 3.5-5mm, and M4 with 5.5mm and larger. 

Use a M2-M1.8 converter to allow a M1.8 cord to fit M2 sized tips

Use a M4-M2 converter to allow a M2 cord to fit M4 sized tips.