Use bullet points to clearly list the product's features and compatibility.

• 1x Brand New Replacement Battery EB-BR810ABU

• 1x Free Tool Kit (to assist with installation)

• Capacity: 270mAh (Verify this detail from the product packaging)

• Compatibility: Specifically for the Samsung Galaxy Watch 42mm (SM-R810, SM-R815, SM-R815U)

• Note: Replacing the battery in smartwatches can be difficult and may require technical skill. Please check YouTube for a repair guide before attempting.