The InfiRay Outdoor BOLT Series Battery Extender IRAY-AC37 is designed to extend the battery life of your BOLT Series thermal weapon sight by more than 75%. This extender threads directly onto the 18500 battery compartment, allowing the use of a flat-top 18650 battery. Compatible with models such as the BOLT TL35, TL35V2, TH35C, TH50C, TH50CV2, and TD50L, this battery extender ensures longer operational time in the field. Made from durable materials, the IRAY-AC37 is a reliable accessory for hunters and outdoor enthusiasts seeking extended battery performance.