Any effect that provides overdrive, distortion or filter falls under Transducer effects. Youll find effects like Megaphone, Radio, Amplifier Emulation and more here. Always take care when using transducer effects in a live situation. Due to the extreme gains and eqs imparted on the signal, these effects are very prone to feedback. For more information on Transducers see: Wikipedia Transducer and Wikipedia Distortion
Keywords: What is Transducer?