These devices contain four independent 2-input NAND gates. The open-collector outputs require pull-up resistors to perform correctly. They may be connected to other open-collector outputs to implement active-low wired-OR or active-high wired-AND functions. Open-collector devices are often used to generate higher VOH levels. The SN5401 and SN54LS01 are characterized for operation over the full military temperature range of -55°C to 125°C. The SN7401 and SN74LS01 are characterized for operation from 0°C to 70°C.