The Ibanez ZR Tremolo Bridge is the first Ibanez bridge to feature a "Zero-Resistance" (ZR) system, enabling the guitar to instantly return to its 'Zero-Position', which is the locked-in tuning of the guitar after use of the tremolo arm. This is achieved through use of ball bearing connections used to mount the bridge to the body of the guitar. The ball bearings allow the ZR to effortlessly tilt up and down and return to 'Zero-Position'. The Ibanez ZR is one of very few tremolo bridges relying on the ball bearings as pivots.
The ZPS (Zero Point System) is also part of the ZR tremolo bridge as it ensures tuning stability and an easier set-up of the tremolo, among other benefits.
The ZR tremolo bridge was introduced in 2003, the S1620FB is an example of guitar using it. Discontinued in 2008, three of its derivatives were put to the market: