The 15" Bosphorus Traditional Crisp Hi Hat Cymbals are fully lathed on both sides, Bosphorus hi-hat tops and bottoms are hand lathed as pairs for a perfect match. Weights include Dark, Crisp, and Bright - from lightest to heaviest. Best-selling Dark weights are very responsive with a low fundamental pitch. Crisp weights are more penetrating while the Bright weights are better for high volume applications.