Just finished ME3 a few days ago so...... an Omni Tool /Omni Blade with flip out blade.
Made from trans-orange 2.5mm sheet acrylic (laser "cut", heated and hand bent) with a few 4-40 screws/nuts and straps here and there
The results of trying to understand the laser "cutter" at my job
The machine has certainly seen some better days and, when it comes to anything over 1mm, it becomes a laser engraver. But with a little trickery and some hand tools I managed to free the parts from their sheet plastic prison.
Heated in oven at 325~350 for 15 min (with a little spot help from heat gun)and then bent by be-gloved hands into its final shape