The 4542264 is the Fluke BT521ANG Advanced Battery Analyzer with angled test probes, designed for comprehensive testing and maintenance of stationary battery systems. It measures internal battery resistance, DC and AC voltage, DC and AC current, ripple voltage, frequency, and temperature with high precision across multiple ranges. The instrument features automatic or manual sequence testing of battery strings with automatic measurement storage, eliminating manual button presses for each measurement, and stores up to 100 profiles with 450 batteries each. All measured values are automatically captured during testing and can be reviewed on the instrument before downloading for analysis. The BT521ANG is ideal for maintenance, troubleshooting, and performance testing of individual stationary batteries and battery strings, providing reduced testing complexity and an intuitive user interface for field technicians.