Steve wrote:
Is it the lower the mm, the higher the power?
Some eyepieces say x100 or x175 etc...

Hi Steve,

you're right there. According to

http://astunit.com/tutorials/telescope.htm

the magnification of a telescope is pretty close to
(focal length of objective)/(focal length of eyepiece)

So, the lower the focal length (mm) of your eyepiece, the higher the
magnification. E.g. my telescope has 1000mm focal length, so if I use my
10mm eyepiece that would yield 1000mm / 10mm = 100x magnification.
(AFAIK you can't tell the magnification of an eyepiece without knowing what
telescope it's used with, so the magnifications those eyepieces state are
for telescopes with one focal length only)

HTH,

Joerg

--
Joerg Glissmann
remove pants to reply.. :-)