Pro Grade Precision™ 4-1/2" x 2-1/2" 180 Grit Dust Channeling Sanding Sponge (2503TRI-180-CH) by 3M®. Keep your surface clean as you hand sand with the 3M™ Pro Grade Precision™ Dust Channeling Sanding Block Sponge. Featuring innovative channels on one side and a flat surface on the other, this two-in-one sanding sponge is great for detail work and flat sanding. Made with premium minerals and ultra-durable foam, this sanding sponge lasts one job to the next and lets you easily control the direction you are sanding. An innovative coating helps reduce clogging, and you can rinse the sponge and reuse it. Tell extra dust to take a hike and reach for the multitasking power of the 3M™ Pro Grade Precision™ Dust Channeling Sanding Block Sponge.