This bracket should attach to most commonly found extruder assemblies found in Prusa/Mendel i3's and similar kits, like the older Big Builders. It mounts in-between the primary fan and the heat sink, taking up a space where some printers have included spacers to fill this spot. Positioned as close to the nozzle as I could figure for a large NPN transducer that doesn't add a lot of additional hardware or interfere with the blower fan. Uses no additional screws, all you need are the mounting nut/tooth-washers your transducer will have most certainly come supplied with.
Could probably print at 15-30% fill and be just fine, but for structural parts (even holding something light) I like to just blow an extra couple pennies of filament at it. It will print fine without support either flat or on its side (default).