Blade Quattro Switching Power Supply for Four Raspberry Pi Boards - 

BitScope Blade Quattro is a desktop, rack or wall mountable power and mounting solution for up to 4 Raspberry Pi computers. It solves the power problem when using the Raspberry Pi in industrial or other critical applications by providing constant, regulated power for up to 4 Raspberry Pi units and 16 USB devices (connected via the Raspberry Pi's) from a single on-board 5V switch mode power supply. It can be used with simple plug packs, batteries, low cost uninterruptible power supplies (UPS) and even passive power over ethernet (PoE) solutions. Full access to each Raspberry Pi's I/O including I2C, SPI, UART, PWM and GPIO is provided via the Blade HUB CAP expansion socket underneath each Raspberry Pi. Connect personality cards (e.g. a real-time clock, operation status displays, or almost any other physical I/O that conform to these standards). Ideal for creating computer clusters, private cloud servers or server farms and experimenting with containerization.