Tremolo pedals are a bit more distinct than chorus, phase and flange effects. However they're still a form of modulation. It's modulation of volume moving it up and down at a certain speed, and following a certain wave form (usually square). Certain pedals let you change the wave form, others bring other modulation into the mix, and some even offer double tremolo effects.
Tremolo Pedals
Walrus Audio Walrus Audio Monument
£192.00
Source Audio Source Audio Ultrawave Bass
£258.00
Source Audio Source Audio Ultrawave
£258.00
Old Blood Noise Old Blood Noise Endeavors Visitor
£192.00
Old Blood Noise Old Blood Noise Endeavors Whitecap
£185.00
Source Audio Source Audio Vertigo Tremolo
£175.00
£299.00
Electro Harmonix Electro Harmonix Mod 11
£149.00
EarthQuaker Devices EarthQuaker Devices Hummingbird v4
£190.00
Walrus Audio Walrus Audio Janus Fuzz / Tremolo
£280.00
Empress Empress Effects Tremolo2
£249.00
£475.00