The K-D Tools KD 2125 is a 14 mm Cylinder Head Rethreader Kit. It repairs damaged 14 mm spark plug threads by opening hole with a reamer/tap and screwing insert onto the spark plug. The spark plug socket is used to install spark plug. The set includes 1 each of 4 inserts 3/8, 7/16, 1/2 and 3/4 reach and thread locking compound.
K-D Tools KD 2125 14 mm Cylinder Head Rethreader Kit - furniture-locator.com