This Bundle has two items: the Apogee Instruments SQ-420X Smart Quantum Sensor, USB; and the Apogee Instruments AM-320 Saltwater Safe Sensor Wand. The Apogee Instruments SQ-420X Smart Quantum Sensor, USB, can be connected directly to a computer (Windows or macOS X) for taking spot measurements or graphing and datalogging real-time PPFD using the included ApogeeConnect software. The sensor can also act as a stand-alone PAR datalogger by simply connecting it to most standard 5 V DC USB power plugs. Internal memory within the sensor head is capable of storing 10,000 user-specified periodic measurements that can be downloaded as a CSV file to a computer for analysis. Resolution - 0.1 µmol m-2 s-1. Calibration Factor - custom for each sensor and stored in the firmware. Measurement Repeatability - less than 1%. Field of View - 180 degrees. The Wand is for placing the SQ-420X Sensor in hard to reach places.