The Crystal Monitor PSG Series systems (20-B and 20-S) are small, yet powerful wireless PSG system with a complete PSG software package. Small and untethered, these systems integrate the headbox, amplifiers, transducers and data telemetry into one handheld unit. Eliminating the need for separate amplifiers, cables and networking equipment allows for fast setup and rearrangement. Data storage on a removable SD memory card allows the system to be used for unattended studies or provides immediate data back up. The simplicity of the system makes it uniquely suited for the traditional sleep lab, as well as non-traditional settings such as inpatient monitoring, sleep lab hotels and home testing.