There are three known types of recorder: the standard recorder (txistu), the txirula (smaller) and the silbote. They differ in size and tone.
The standard txistu (wooden part) is 422 mm long. The outer diameter of the head is 30 mm. The outer diameter of the lower section is 20 mm. The head is 25 mm long. The internal bore has a diameter of 13 mm. The reed slot is 15 mm wide. The reed faces the lower part of the mouthpiece.
The holes are drilled using a 9.5 mm drill bit. The distance from the lower part to the centre of the first hole is 53 mm; to the second, 80 mm; and to the third, which is below, 114 mm. The total length of the mouthpiece shall be 43 mm. Width: upper part, 15 mm; lower part, 13.5 mm. The end plate is 27 mm from the lower part. The reed will be 83 mm long, 16 mm wide and taper to a point at the bottom, where the ring is attached.
The txistu features a set of rings which are made to order, depending on the type or category of instrument (boxwood, palo santo or ebony), and are made of brass, white metal or silver. The head will be made of sheet metal and ends where the slot for the reed begins at the front. At the back, it will have a recess, just like the wood, to prevent the sharp edge from causing discomfort against the chin.
The lower ring (also made of sheet metal) is 14 mm wide. The remaining six rings are half-round and 5 mm wide; at the bottom, the last ring has another ring crossing it vertically, into which the ring finger is inserted, thus holding the instrument in place. It is 19 mm wide.
The material used for the standard classical txistu and the silbote can be ebony, boxwood, and it has even been made from the exotic paddu wood. This, like boxwood, is light in colour: these txistus must be stained; with wear they lose their colour and are not pleasing to the eye. Nowadays they are also made of metal and plastic. The quality of the sound varies depending on the material used.
The rings, if not made of silver, lose the chrome plating applied to brass ones. Quite a few have also been made of nickel silver, which holds up rather well. There are others made of stainless steel.
The txistu has a ring at the bottom of the instrument, into which the ring finger is inserted. The little finger is free to close or open the lower end of the tube. The index and middle fingers are placed over the two holes at the top; the thumb is placed over the lower hole.
The txistulari carries a small drum hanging from his left arm, which is taller than it is wide.