Maracatu drums are called "Alfaias". They're large drums from Pernambuco (Brazilian Northeastern state). Sometimes, they are also refered to as "surdos de cordas" (rope surdos). They are part of the bass-drum family, along with bombos, surdos and zabumbas.
Their main feature is the rope tuning. They have two cow leather - or goat hide heads clamped to the wooden barrel with wooden hoops. The hoops are threaded with rope, which is responsible for the heads' tension.
Alfaias are played with specific mallets.
Their construction is similar to 19th Century US and European military field drums, bombos, and other Latin American wooden bass drums.

The term "Maracatu" covers different expressions of the Carnaval artistic traditions in Pernambuco, including percussion-based music, singing and dance.
In musical terms, Alfaias play an essential part in Maracatu: they not only play the main beat, but also tricky variations and solos, which is a musical feature directly inherited from the African roots of this music.

This model from Contemporãnea (Brazilian leader in percussion-making) has a, precise low-pitched sound. Pretty light, it is a mid-size drum and can be used to play basic Maracatu patterns as well solo-parts. Impeccable making and finishing quality.

20 in diameter
18 in (45 cm) deep
Goatskin
Rope tension
Weight 4.5 kg