Check the listing for details. MXR M291 Dyna Comp Mini Compressor pedal w/ ECB-003 9v power supply. Condition: New. Listed at 109.99 USD. MXR M291 Dyna Comp Mini Compressor pedal w/ ECB-003 9v power supply The MXR M291 Dyna Comp Mini Compressor with a Dunlop ECB003 9v power supply. The Dyna Comp Mini Compressor combines classic tone and modern convenience in a housing that's nearly half the size of the original, featuring an all-new Attack switch to toggle between slow and fast attack times. The Dyna Comp Mini Compressor combines the best of classic tone and modern convenience in a housing that's nearly half the size of the original. Thanks to its rare CA3080 metal can integrated circuit (IC), this pedal yields quieter operation, greater transparency, and increased dynamic range. An all-new Attack switch toggles between slow and fast attack times. Download owners manual here