After the Bigsby, the next major development was Leo Fender's "synchronized tremolo", the device that introduced the term "tremolo arm" (US Patent 2741146 filed in 1954, issued in 1956). First released in 1954 on Fender's Stratocaster, the simple but effective design offers a greater range of pitch change than the Bigsby, and a better capability for up-bends. Fender wrongly labeled the arm as a "tremolo arm" rather than a "vibrato arm", conversely referring to the tremolo circuit on his amplifiers as "vibrato".