The smallest trumpets are referred to as piccolo trumpets. The most common of these are built to play in both B and A, with separate leadpipes for each key. The tubing in the B piccolo trumpet is one-half the length of that in a standard B trumpet. Piccolo trumpets in G, F and C are also manufactured, but are less common. Many players use a smaller mouthpiece on the piccolo trumpet, which requires a different sound production technique from the B trumpet and can limit endurance. Almost all piccolo trumpets have four valves instead of the usual three—the fourth valve lowers the pitch, usually by a fourth, to assist in the playing of lower notes and to create alternate fingerings that facilitate certain trills. Maurice André, Håkan Hardenberger, David Mason, and Wynton Marsalis are some well-known trumpet players known for their additional virtuosity on the piccolo trumpet.