Features: 1. Specific Application: The fuel system coupler fitting tool is designed to be connected to the hose of ONI581T. This tool is suitable for use with Detroit Diesel S60, MBE900, MBE4000, Cummins, and Caterpillar engine trucks. 2. Excellent Feature: This tool is designed to connects to a "Compu-Check" quick connect fittings and used together with ONI581T J- DETROIT DIESEL S60 MBE 900 MBE 4000 DD13 DD15 FUEL SYSTEM PRIMING PUMP OTC5869, similar to J-47912-QC. 3. Tool Specification: 1/4 inch NPT male threads and 13/16 inch hex size .