The Stan's NoTubes Sentry MK3 27. 5in Boost Wheel is a sturdy aluminum wheel built to accommodate the increased width of modern mountain bike tires. With a 32mm internal rim width, the Sentry MK3 provides an ideal profile to tires ranging from 2. 5 to 3. 0-inches in width, letting you run everything from wider trail rubber to plus tires. And as a pioneer of tubeless wheelsets, Stan's has done extensive testing to determine the best rim width for a given range of tire sizes. This technology is referred to as "WideRight," and it allows the tire to achieve its proper shape, which is the foundation for a great handling, fast-rolling, and responsive bike. Not only is the Sentry MK3 intended for the higher volume rubber prevalent on modern trail bikes, but it's also designed with their proprietary Bead Socket Technology (BST), which is a fancy way of saying the rim attaches to the bead of the tire, instead of merely pushing it down farther into the sidewall. Because of this BST, you'll find it's increasingly air-tight and free of burping in tubeless setups. Just as importantly, this technology decreases the tire's vulnerability to slashes by running it in a truer, rounder shape without pushing the sidewall outwards where it's susceptible to damage. Compared to the more modestly priced Sentry S1 wheels, the Sentry MK3's rims are made of higher grade 6069 aluminum. You also get alloy nipples instead of brass, and nicer Sapim Force spokes. Together, these changes save about 130-grams of weight without sacrificing any strength or durability. The rims are laced to Stan's Neo hubs equipped with a reliable 6-pawl system that offers 10-degree engagement, which is more responsive than many wheels in this price category. This revised version of the Neo hubs now features triple freehub bearings for increased axle stability, allowing them to handle even greater vertical and torsional loads. They also use the Durasync freehub system, which engages all 6 pawls simultaneously for u...