This is the Astro Flight "Blinky" Balancer for Thunder Power Batteries. FEATURES: This battery balancer is designed for use with LiPo batteries Accepts one to five cell Thunder Power, Apex and other battery packs with 2mm connectors INCLUDES: One Astro Flight "Blinky" balancer for Thunder Power batteries One instruction sheet SPECS: Length: 1.06" (27mm) Width: .70" (18mm) Height: .19" (5mm) COMMENTS: For questions regarding this item one would need to contact Astro Flight directly.