Its definately not a "needed" piece or equipment but takes second guessing your equipment away. You only have to do it once or when you move or bang around your equipment.

Another toy I figure. I got em a few years ago when I was on a quest for the very good digital scale. I tried all the brands and didn't find any of them to suit my needs. I brought home a ohaus counting scale from work that is very accurate, but only works in grams and its a counting scale which is not needed.