Sony WI-C100: Should You Buy the 25-Hour Neckband?

The Sony WI-C100 (Blue) is a neckband-style Bluetooth earphone. The buying decision comes down to three things: long battery life, splash resistance, and app-based sound adjustment. This guide uses only the supplied product facts and Sony's own product information. Anything not established there is marked as unverified rather than assumed. Core specs: Bluetooth 5.0, SBC and AAC codecs, and a 9mm driver, per Sony's product page [S2]. Weight is listed at about 20g, worn around the neck in a band format [S2]. The color lineup is Blue plus Black, White, and Beige [S2]. Battery is stated by the manufacturer as up to 25 hours of playback, with quick charging giving 60 minutes of playback from a 10-minute charge [S1][S2]. Talk time is up to 15 hours [S2]. A standby figure appears in the spec table layout but the number is not readable in the supplied text, so standby time is unverified [S2]. Charging is via USB Type-C, and Sony explicitly states a USB Type-C cable is not included [S2]. Budget for a cable if you do not already own one. Splash resistance is rated IPX4, described as protection against sudden rain and sweat during sport [S1][S2]. This is not waterproofing; do not expect submersion or high-pressure water resistance. On sound, Sony describes DSEE upscaling of compressed audio and an equalizer in the Headphones Connect app [S1][S2]. Importantly, DSEE and the equalizer are off by default and must be enabled in the app, and the app works only over Bluetooth [S2]. These are manufacturer claims; the supplied sources include no independent listening test or fit assessment, so real-world sound character and comfort are unverified. Noise cancelling is not included [S1]. Price shown is ¥3,812, with a listed reference price of ¥2,599. Sony's own store lists ¥4,950 including tax [S2]. Prices vary by seller and timing, so check the current listing before buying. Bottom line: a reasonable candidate if you want long runtime without cables and want some sweat and rain tolerance. Skip it if noise cancelling matters, if you do not want to buy a USB-C cable separately, or if you need independent sound-quality evidence before deciding.