Laboratory balance is used to measure an objects mass to a very high degree of precision. In its conventional form, this class of measuring instrument compares the sample, placed in a weighing pan and suspended from one end of a beam with a standard mass or combination of standard masses in a scale pan (scale basin) suspended from the other end. It consists of a beam with a friction-free fulcrum, a pointer, which attaches to the beam and amplifies deviation from the balance position, and fractional weights, which are applied along the beam's measuring arm. Specifications for laboratory balances include capacity, resolution, platform width and length, display, interface, and ratings. Some laboratory balances have an analog display such as a needle.