This is an interesting kind of battery holder, usually you'll see ones that are designed for holding like AAA's or something. This battery holder is designed to clip into and hold camcorder batteries. Specifically, the common Canon LP-E6 rechargeable Lithium-Ion Battery Pack (7.2V, 1800mAh). We also have a holder for the SONY NP-Fxx series and Pansonic CGR-D28/CGA-D54 series.