The 521 bass recorder from Aulos is designed for ensemble playing. It is pitched in F and its notes range from f (below middle C) to g'' (two octaves above).
Being such a long instrument, the bass recorder can be a little uncomfortable to play, but Aulos have incoorporated an 'f-bend' neck so that the player's arms don't have to stretch quite as far, and comparatively closely-spaced keyholes for a more comfortable hold overall. Being made from ABS plastic, the instrument is also relatively lightweight.
The recorder features a curved windway, a concave bell and a double f/f# key / double g/g# keyhole (for easier fingering). It is supplied with a brown leatherette bag a cleaning rod, joint grease and a sling.