The size of the insert refers to the inside diameter and thread pitch.
M12x1.25 SS Insert 24.0 Part #12126 Stainless Steel Metric Insert Size M12x1.25 Insert Length Metric is 24.0 Professional Thread Repair TIME-SERT® thread repair system the ultimate way to repair threads in stripped or damaged holes. This listing is for (1) ONE insert Please note: The size of the insert refers to the inside diameter and thread pitch.