Wire stripper — uses sections of a snap-off utility knife as blades (see photo). I had a few spare segments at home and wanted to put them to use.
Insert the blade into the parts as shown in the picture (be careful not to cut yourself). Before fitting the blade, apply a few drops of adhesive — I used T-8000, but any similar glue will work — so the blade will hold securely in place and can be replaced after wear.
 

Important: Use the tool with caution to avoid damaging cables and, above all, to protect your health.