All user reviews for the M-Audio Sp-1

I have used this pedal with plenty of keyboards of different brands and have never had a problem to make it work. The only downside is that the mechanism is noisy: Every time you press the pedal you hear a loud "clack." It's not a problem if you play at high volumes (when you play with monitors, for example), but when you play at home at moderate volumes, it's annoying.

Keyboard sustain pedal.
It's made of metal with a rubber pad.
Its cable is extended by a standard 1/4" jack.
It further features a polarity switch for universal compatability, which allows you to select the operating mode.
Mode 1: Press = closed contact; release = open contact.
Mode 2: The opposite.
I bought it for €15 in a store in Paris.

The Sp1 is made of metal, very heavy, so it doesn't slide and seems super sturdy. BUT after only one year, both plastic supports (top and bottom) have come almost off, and the first signs of it becoming loose appeared quickly after I bought it.
It's better to go for other models like the Yamaha FC5, which has a similar design and is a bit more expensive, but doesn't come apart..