Turn Coordinator
A traditional turn coordinator is essential a combination of two instruments: a rate-of-turn indicator, and an inclinometer.
Inclinometer
An inclinometer shows the quality or coordination of a turn, either slipping or skidding.
Turn-and-slip Indicators vs Turn Coordinators
Both the turn and slip indicator and turn coordinator are gyroscopic instruments, but they differ slightly in what they display.
The turn coordinator is a gyroscopic instrument which displays roll rate and rate of turn. The turn-and-slip indicator only shows rate-of turn.