When procuring an ESD (Electrostatic Discharge) mouse, the most critical factor is the surface resistance, which should typically range between 10^6 to 10^9 ohms to ensure controlled dissipation of static charges. You must verify if the mouse is made of inherently dissipative materials rather than just a temporary anti-static coating, as coatings can wear off over time. Additionally, ensure the optical sensor resolution (DPI) is sufficient for precision work, and check for low-outgassing properties if the device will be used in a Class 100 or higher cleanroom environment.