Description: Name: Hot bed aluminum substrate Material: aluminum substrate Size: 328x328x3mm Effective print size: 300*300*3mm 3mm thick aluminum substrate For 3D printer hot bed aluminum substrate, 24V Package Includes: 1Pcs Aluminum Heated Bed Note: Power adapter is notincluded. 300mm on the motherboard is just a mark, not the actual size, the actual size is 328mm MK2a and MK3A are mutually versatile