The sub-great bass recorder, also known as contra great bass and contrabass (), is a recorder with the range C–d1 (g1). It is manufactured in both bent ("knick") and square designs. The design with a square or rectangular cross-sections was first patented in 1975 by Joachim and Herbert Paetzold. They are made from plywood and have a doubled-back bore like a bassoon, which reduces the exterior length of the instrument. They also have wooden keys (). Through this special and proprietary design, the instrument can be played with a very short bocal.