In order to improve the permeance and strengthen {HEAD ~ the magnetic flux density}, there exists {TAIL ~ a method} of narrowing the breadth of a magnet across the circumference of the roller from a distance extending toward the center thereof 
In order to improve the permeance and strengthen { HEAD ~ the magnetic flux density } , there exists { TAIL ~ a method } of narrowing the breadth of a magnet across the circumference of the roller from a distance extending toward the center thereof
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH