This is an International truck clamshell type piston ring
compressor. This ring compressor has a 4.589" bore diameter.
This tool assures proper piston installation, reducing the possibility
of broken rings. This ring compressor is made in the U.S.A. and is made
for use with the Later International Navistar trucks: DT 466/ 570, DT
466/ 530E,. This ring compressor replaces the OTC Tools
ZTSE-4396