Rocktron One-Button On/Off Footswitch (Rampage Series) RFS1
Here's a nifty, one-button on/off foot switch. LED lights tell you the on/off status. Internal 9V battery powers the LED.
Links to amp with a single, standard guitar cable (TRS 1/4" ends). This is cool, since most switches hold up fine, but the cable eventually shorts out. With this design, you can simply unplug the cable and replace it.
Steel case construction with side-slides for locking two or more switches together.