hope mono m4 models - 8/3/5???

bluechair84
bluechair84 Posts: 4,352
edited December 2009 in MTB general
I've just bid on a mono m4 and found a question on another auction asking for a number inside the caliper, either and 8, 3, or 5. Apparently 8 is desirable but why is this and what are the numbers referring to?
If I don't get an 8, am I get a duffer?