PLEASE NOTE: This battery is very difficult to install and requires specialized tools. GARMIN WILL NOT REPLACE THE BATTERY FOR YOU. We offer a battery replacement service kit where we will install the new battery for you. For this listing please copy and paste this link: http://www.amazon.com/dp/B014VWDMU2 . This is the only battery that will restore the original performance of your watch! Beware of non-Garmin replacement batteries. They typically only last half as long as the genuine Garmin battery. This is a brand new 30mm x 3.2mm 3.7 volt rechargeable Lithium Ion coin cell battery directly from the Original Equipment Manufacturer that Garmin uses in their watches. The manufacturer, Route JD (formerly Korea Power Cell) uses proprietary technology to provide 30% more battery capacity in the same cell size. Standard LIR3032 Lithium Ion rechargeable batteries will not last as long. These watches are great however, the batteries have a limited lifespan and will degrade over time as well as the number of recharge cycles. Eventually you will have to replace the battery. Replacing the battery requires specialized tools, soldering iron and experience repairing small electronics.