Thank you for viewing. This is a Callahan synchronized tremolo bridge. The string spacing is approximately 11.3mm. I purchased this over 10 years ago, but it didn't fit my guitar's string spacing, so I removed it immediately and stored it. It was kept in a box, so in my subjective opinion, there is no rust and it is in a clean condition. The items included are the bridge, arm bar, springs, tremolo screws, and hex wrench set, but the tremolo screws may not be Callahan's. Also, the spring hanger and fixing screws are not included.