These are great winter tires. The 'studdable' version takes inexpensive studs in the pockets if you like. The studded version has some wicked crowned studs that look like they'll penetrate and grip like nothing else.
Light weight, fast rolling sidewalls and great siping to provide great traction!
Current stock has the Studded ones available in 29 x 2.8 which is the biggest studded 29'er we've found. Studdable versions in the 27.5 x 4.5.