The MCC-SMB is the standard size surface mount brush. The brush head is made with natural fibers. The smaller brush size helps get into those hard to clean areas on your surface mount PC boards. This like all MircoCare replacement brushes are sold in packs of 5. Also available is the MCC-SMB2 which the same size and function of the MCC-SMB with a "Slo-Flo" tip within the flow restrictor. Using less solvent than the standard brush head, minimizing consumer cost and reducing the solvent fumes admitted into the air.