pool cue straightness detector tool, light weight ( frame made by acrylic and plastic fastener ), small size pocket tool.
a) HOW TO USE?
rotate the cue on the tool, eye check if the cue shake or deviation from its original position.
non-load spin time: >20 seconds.
It's eye check tool, give a rough idea of your cue straightness.
If need high precision, kindly move to digital lathe tool.