These anvil bases offer a perfectly flat base to rest the base of your case against whilst measuring it, either the case overall length (CBTO) or when using the comparator kit to measure base to ogive (CBTO) of your rounds.
 
Made of 303 stainless steel and brass.
Single-screw type (thumb screw) is convenient but may interfere with use and may not be as "true".
Dual-grubscrew type will sit flush on caliper jaws, and offer secure gripping.
Our Anvil bases will work with any brand of bullet comparators.