Heating spirals is a resistance wire rolled onto the proper core and ending with an electric outlet in the form of a wire twisted pair (often referred to as the "plait") or a current pin.

Basic information:

A high quality resistance wire Kanthal  by Sandvik (mainly the grades D,A,A-1,AF,AMP,N80)

A wide selection of diameters (starting form 1mm) and power

An electric outlet in the form of a "plait" or pin