Check the listing for details. MBX SURFACE TECHNOLOGIES MMB1 4 6 PK. Condition: New – Open box. Listed at 35.00 USD. The MBX Surface Technologies MMB1 3 ,,,, 5 PK is a set of flap discs specifically designed for sanding and abrasion in metalworking applications. These discs are durable and effective at removing material from various surfaces, making them ideal for use in CNC machining, metal fabrication, and other industrial processes. With a focus on quality and performance, these flap discs are a reliable choice for professionals in the manufacturing and metalworking industries.