The timbale drums are almost always included in salsa. They are played with sticks, somewhat like a rock drum set. When played in this way, they frequently take solos that depart from the usual salsa rhythm patterns. However, they are also used to play one of the signature rhythm patterns of salsa: the "cáscara" pattern. This pattern is not played on the drum head (the top of the drum).
Instead, it is played by slapping one of the drum sticks against the hard outer shell or "cask" of the drum. Like the clave pattern, the cáscara pattern has a 2-3 variation and a 3-2 variation. The clave pattern and cáscara pattern are different from one another, but are typically matched to one another.
Notice that some part of the cáscara pattern always occurs on beat 1.