English double flageolet. Boxwood with brass keys and ivory ferrules and studs. Two wind cutter keys on stock. Five other keys (two on left hand pipe, three on right hand pipe) are block mounted with square flat flaps and leather pads. Sponge chamber stamped: C.GEROCK/79/CORN HILL/LONDON; Stock stamped: C.GEROCK/79/CORN HILL/LONDON; A unicorn's head motif appears above both inscriptions. Left hand pipe and right hand pipe are stamped: C.GEROCK; Left hand pipe has seven tone holes, with numbers 1- 7 stamped down left side and note indicators B,A,G,F,E,D,C sharp down the right. Right hand pipe has five tone holes. The numbers 1- 4 are stamped on the left side and the note names B,G,F,E,D,C,D appear on the key flaps and right side of the holes.
The double flageolet, with its paired duct flutes, is classified according to the system of Hornbostel and Sachs as a 'set of open flutes with internal ducts, with fingerholes and keys'.