Low profile center blocks roll quickly across the trail while the siped transition knobs and shoulder blocks give purchase on almost every trail condition. Dual Tread compound and sealant compatibility in standard or racing (TR) formulas. DTC - Dual Tread Compound is a combination of two different rubber compounds L3R Pro (center knobs) and Stick-E rubber (corner knobs). TLR/TR - Tubeless (Light) Race is the lightest tubeless ready version of tires Kenda offers and also features an improved bead shape for better retention