Adjustable metal micro-coiled cajon strings on the Buler��a Line allow you to dial in your desired level of string sensitivity for different snare effects. Two groupings of five strings span across the inside of the playing surface to deliver a crisp snare sound. These strings are hand wound in the style of master cajon builder, Jos�� "Pepote" Hern��ndez Diaz, and each set is adjustable with the included key. The 9-ply 12mm thick Baltic Birch resonating body develops the sound into a full, punchy tone that projects with clarity and warmth. Inside the Buler��a Line of cajons is a special bass reflex system that enhances low end notes for a deeper bass sound.