|The box in
the lower right hand corner is a picture of a ball point pen. It shows that the distance across the tip
(rolling ball) of the ball point pen is approximately 1000 microns. Considering the membrane pore size, you
could fit 1000 – 2000 membrane pores across the tip of the ball point
pen. BHA-Tex will filter down on
average to anywhere between .5-1 micron in size.