Innovative Components AH-COMBOXSET Thread Detective/Thread Identifier Inch and Metric Combo set. ROHS Steel identifiers conveniently housed in a sturdy, living hinged box. Permanent, easy to read size markings won&rsquo;t peel off and are chemical resistant tested and approved. Set includes Inch Sizes #6 thru 1/2 in both coarse and fine threads and Metric Sizes M4- M12 in the most common pitches.