Compatible with Galaxy Watch 4 (40mm) and Classic (42mm) models. Cameron Sino variants are noted by reviewers on Newegg for potentially higher capacity than the original brand replacement. iFixit Samsung Gear S3 Battery Go to product viewer dialog for this item.
Specifically for the T-Rex and T-Rex Pro series, these lithium-polymer batteries are rated for approximately 400 to 500 charge cycles. Replacement Kits with Tools smart watch battery buy
For less common models, generic Li-ion polymer batteries like the YDL 3.7V 380mAh Rechargeable Lithium Polymer Battery Go to product viewer dialog for this item. Compatible with Galaxy Watch 4 (40mm) and Classic