Arisun Sharktooth 26x4" Folding Studded Tire - Rambo Bikes Canada - Official Site
Chicargobike: Do studded winter bike tires make sense?
Winter Bike Tires -
45NRTH Wrathlorde Studded Fat Bike Tire 26 x 4.2, 300 XL Concave Carbide Aluminum Studs,Tubeless, Folding,120tpi, Black - The Inside Line Mountain Bike Service Ltd.