Logic:For MEGA compatible Atmega2560 and Atmega32u2 processors are compatible with all RAMPS class firmwareCrystals for both usb and mcu (timing accurate to 10ppm)Thermistor jacks + 4th Thermistor circuit on ZProbe.Motor Drivers:4 Trinamic TMC2130 1/256th microstep motor drivers(2 connectors on Z for Prusa Mendel and other dual Z printer designs)SPI Control of stepper current instead of PWM.Microstep mode configured by MCU through firmware (SPI, no jumpers needed)PWM DC outputs (Extruders, Fans, Etc.)4 outputs (1 Extruder, 1 BED, 2 low power (fan,etc)Low resistance mosfets for Indicator led for each channelFANS have 3pin fan connector.FANS have 5V instead of 12-24V power source.FAN connectors have tachometer feedback pin to the MCU to measure fan speed in capable firmware.Power2 power input railsHeated Bed, 15A 12-24V (15A dedicated fuse)Primary Power 10A 12-24V: Motors, Logic & Fans (5A dedicated fuse) + Extruder (5A dedicated fuse)Built in SMPS for 5V generation from the Motors, Logic & Fans railProvides 5V power to FANSConnectors4-pin motor,zprobe plug - Molex 5057-94043-pin fan plug - Molex 5057-94032-pin thermistor, mech. endstop plug - Molex 5057-9402Colour: BlackMaterial: PCBSize: 20 x 14 x 7CMPackage Contents:1 x data cable2 x gray cable1 x Einsy Rambo 1.1b motherboard1 x 2004lcd1 x terminal4 x Heat sink1 x adapter boardOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.