This tool will vent air pressure in the Integrated Drive Generator (IDG) installed on the 737 CFM series engines equipped with Hamilton Suntrand P/N 761574B generators. It is designed to lock and hold the vent down while servicing the unit. It is precision machined from AL 6061-T6. (This product used to come with a vinyl streamer but it is no longer available. The price has been discounted the price for this reason. The ability to install a streamer will remain machined into the product. )