Ettore's Pro+ Microfiber Sleeve is made of, as the name states, microfiber. However, not just any microfiber, this fabric has increased water retention unlike any other sleeve on the market. Additionally, a white scrub pad in included on the end to focus the hard to remove junk.
Between water retention, scrubbing power, and cost, this is our favorite exterior scrubber. Just wish the small scrubber on the end would last longer. :)