We have the FloScan Model 5410-20A-1. 0-10 GPH scale, single engine, for all 4-cycle outboards PLUS 2-stroke Ficht, Optimax, and HPDI outboards (76 hp - 150 hp).
It looks like the model 5500. We love our FloScan and to us it is a very important instrument to have. Helps us keep track of gas used on an Excel spreadsheet so we know when we better be heading for the gas station. The Excel sheet also calculates the amount of Sta-Bil we need to add after each fill up.
Highly recommend FloScan.