This is a product review, not a seller review. I bought ST-173 from another seller. However, I hope my experience will be helpful to anyone planning to evaluate or use one of these devices. The Reed #ST-173 may correspond to the Extech 407760 USB Sound Level Data Logger and the same problems MAY occur. The software supplied with ST-173, V1.0 DOES NOT WORK and crashes. The working software, in my case V1.2, had to be downloaded from [.]. In addition, the installation under Windows 7 does not install the USB drivers required for the software to communicate with the data logger. Installing software on XP works. The data logger works in two modes, automatic and manual. Automatic means that data recording starts as soon as the data logger is configured by the software. Manual means that data recording starts when the button on the recorder is pressed. It is IMPORTANT to note that in manual mode, the data logger MUST be connected to the host's USB port when the start recording button is pressed. In addition, the data logger MUST NOT be turned off before uploading data to the host. This is an unexpected behavior that limits the usefulness of the logger. It is advisable to set up the device on the host, then bring it into the field, turn it on and start collecting data. When the acquisition is complete, turn off the instrument, return it to the lab, and reset the data to the host. HOWEVER, THIS IS NOT THE PERFORMANCE OF THE DEVICE. This behavior severely limits the usefulness of this device. Batteries in staples cost $20 each and last three days. This device does not do what I need. The supplied software does not work. Batteries are prohibitively expensive. The first one I ordered was dead on arrival. So a start I hate this..