RepRap Mega Pololu Shield, or RAMPS for short.
It is designed to fit the entire electronics needed for a RepRap in one small package for low cost.
RAMPS interfaces an Ard Mega with the powerful Ard MEGA platform and has plenty room for expansion.
The modular design includes plug in stepper drivers and extruder control electronics on an Ard MEGA shield for easy service, part replacement, upgrade-ability and expansion.
Additionally, a number of Ard expansion boards can be added to the system as long as the main RAMPS board is kept to the top of the stack.
Version 1.4 uses surface mount capacitors and resistors to further cover edge issue cases.
Suitable for hot bed resistance and power: ≥2Ω 12V 70W. Otherwise, it is easy to burn the terminals.
Used in conjunction with the regulator block. You can bring a bigger hot bed.