The Bach 42A Stradivarius Professional Tenor Trombone with Hagmann Valve is a great choice for the player looking for an even less resistant F Attachment. The Bach 42A Trombone features the Rene Hagmann Free Flow (TM) valve, which eliminates the back pressure that occurs in the F attachment with normal rotor systems. The 42A Hagmann Tenor Trombone offers an open response in all registers. The Bach 42A Trombone is available in lacquer (42A), lacquer with gold brass bell (42GA) or with a lightweight slide in lacquer (LT42A) or with a gold brass bell (LT42AG).