1/4" is a pair of standard sized large TRS jacks with flexible rear-panel headers. Hook your 1/4" to any intellijel-format audio modules, like our "IO" to act as front panel inputs, outputs, or a combination of both! 7hp may seem like a strange width, but this was chosen for good reason - this was the minimum width the hardware fit inside, and when paired with another 1/4" or a 3.5mm, you're left with an even number of hp occupied. Each 1/4" also ships with a 1u1hp blank panel just in case! Width:7hp Depth:45mm (accounting for attached three pin cables) Passive power:+12v: N/A-12v: N/A+5v: N/A Our modules DO NOT include mounting screws! With the variety of preferences and sizes, we have decided not to provide mounting screws with our modules.