Vernier, dial, and digital calipers all perform outside measurements and many also perform inside, step, and depth measurements. General purpose digital calipers are not used in harsh environments where the instrument could be damaged by liquids or solids. Harsh-environment digital calipers are IP-rated for use in washdown environments where they may be exposed to splashes of coolant and cutting fluids. Dial calipers have adjustable jaws that slide along a beam with measurements displayed on a graduated dial. Digital and dial caliper gauges have spring-loaded arms fixed to a dial or digital indicator. Specialty digital calipers are designed for specific applications and measurements. Vernier calipers have a main fixed scale paired with a secondary vernier scale to determine high-precision measurements. Accessories such as depth attachments, jaw extensions, and replacement battery covers allow users to customize their equipment and keep it operating efficiently.