Abstract: A hydration bladder fluid level detection system includes a pack having a hydration bladder removably secured therein; a display in communication with a power source and to attach to the pack, the display having; a high level indicator; and a low level indicator; a detector system, including a high level probe in communication with the high level indicator and to detect fluid at a first level in the hydration bladder; a low level probe in communication with the low level indicator and to detect fluid at a second level in the hydration bladder; and a power supply probe in communication with the power source and to complete an electrical circuit with the high level and low level probes as circuit components; fluid dropping below the first level deactivates the high level indicator by breaking a circuit leg running between the high level probe and the power supply probe; and fluid dropping below the second level deactivates the low level indicator by breaking a circuit leg between the low level probe and the pow

Abstract: The invention provides polymeric PTC compositions and electrical PTC devices with higher voltage capability and improved electrical stability. Depending on device design, the composition can be used in low to high voltage applications 6 volts up to 240 volts.