A really versatile attachment for the Proxxon Table Top Hot Wire Cutter 230/E, great for reproducing geometric shapes of all kinds.

Fixes to the machine by sliding into the groove on the table top and can be clamped down at 0° - 90°. Also includes a variable angle guide on the fence itself for the reproducing complex shapes.

You could also just use the fence as a wall or guide for your material to butt against as you make your cuts.