Heuer Silverstone 110.313B 42mm 1970s Heuer Silverstone 110.313B 42mm 1970s The dial and hands are in excellent condition, with strong colour, clean surfaces, and crisp printing throughout. There is no visible degradation, spotting, or damage, and legibility remains clear across all indications. The case is in very good vintage condition, showing light hairline scratches consistent with careful wear over time. The original case form and geometry remain intact, with no signs of heavy polishing. The watch is fitted with its original stainless steel bracelet, which is in excellent vintage condition with minimal stretch and light hairlines commensurate with age. As this watch is now over 30 years old, it should be treated as a vintage timepiece. Despite its original sporting purpose, it is not recommended to wear this watch whilst swimming or expose it to moisture. Performance and Testing Results The movement has been tested on a Witschi WAIO professional timing system. Testing was carried out across multiple positions, with the following results observed: rate readings ranging from approximately -6 seconds per day to +16 seconds per day depending on position, beat error measuring between 0.1 ms and 0.5 ms, and amplitude readings generally in the low to mid 200-degree range, with higher amplitude recorded in dial-down position. These results indicate stable and consistent performance for a vintage automatic chronograph of this era. The test was completed successfully, and the movement is operating within an acceptable range at the time of assessment. Vintage Use Note Given this watch is a vintage timepiece, it should be treated as such and we recommend avoiding swimming or water exposure, even if it has passed water resistance testing at the time of assessment. Google Crown Vintage Watches for More info. Crown Vintage Watches is a licensed NSW second hand dealer in Sydney, Australia  Item is also listed elsewhere. (Chrono 24, my website)  We ship worldwide with Fedex or DHL to most countries fully-insured. We ship domestically with TNT overnight express fully-insured. Licensed second-hand dealer Our company is a Sydney CBD Based Dealer Please be aware, the BUYER is to pay their countries respective import tax. Any questions please ask