I keep a set of these tools in my tool box and use them regularly when setting up lathes or mills. The four different sizes are very handy depending on what kind of interference I want to set up. As others have said, they're not entirely accurate, but very useful in situations where disabling them isn't a big deal.
Kapro 307-08-TMS Try And Mitre Layout And Marking Square With Stainless Steel Blade, 8-Inch Length
18 Review
Empire Level E250M: 12-Inch Heavy Duty Professional Combination Square with Etched π Stainless Steel Blade, Metric Graduations and True Blue Vial - Accurate Measurements Guaranteed
8 Review
Triangle Group TR918 225/45 R18 95V summer
61 Review
π Johnson Level and Tool 400EM-S 12-Inch Heavy Duty Metal Combination Square for Professionals, with Inch/Metric Measurements, Silver - 1 Square
8 Review
Precision Laser Level: Firecore 2X360 Self-Leveling Green Beam Tool With Pulse Mode And Rechargeable Battery For Accurate Alignment And Versatile Use
22 Review
ICEPURE 2PACK Replacement for GE MWFINT, 197D6321P006, WFC1201, GSH25JSDDSS, PSHS6PGZBESS, SGF-G9, RWF1060 Refrigerator Water Filter - Efficient Filtering Solution for Your Fridge
22 Review
π CAMWAY 6 Inch Digital Caliper with LCD Display, Electronic Vernier Caliper, 150mm Stainless Steel Feeler Gauge, Plastic Digital Caliper Set for Zero Setting Inside/Outside Diameter, Depth, and Step Measurement Tool
3 Review
High-Quality Beaquicy Replacement Dryer Lint Filter And Cover Housing Set For Kenmore And LG Dryers (ADQ56656401 And MCK49049101 Models)
19 Review