The way coils are wound can result in different names being applied to them. The most common type is known as a "pancake coil", named after the way the coil looks when laid flat; "ribbon wound" is another name for this method of coiling. Another type of winding is "traverse" or "Oscillated", also known as "bobbin wound" or "spool" due to the fact that it looks like a bobbin of cotton sometimes these can be physically wound onto a plastic spool. http://www.avicmr-steel.com/stainless-steel-coil/