This is a VARTA Industrial alkaline 9V (6LR61) battery, VARTA type 4022, a single primary (non-rechargeable) cell from VARTA's Industrial range, which is sold in bulk packaging rather than retail blister cards for businesses that go through batteries in quantity. Typical uses include smoke detectors, wireless microphone and in-ear monitor bodypacks, guitar pedals and active DI boxes, multimeters, test equipment and toys. Venues, rental companies and AV crews often buy industrial-grade cells by the box so that transmitters and packs can be fitted with fresh batteries before every show. VARTA's data sheet lists the 6LR61 cell as a zinc/manganese-dioxide alkaline chemistry with a nominal 9 V, a typical capacity of 640 mAh (high-resistance discharge), a weight of about 47 g, a volume of 20.8 cm³, a permissible temperature range of -20 to +50 °C and a coded shelf life of 5 years. Maximum dimensions are 48.5 x 26.5 x 17.5 mm (max). AV Distribution sells this item in multiples of 20, so the listed price is per cell but orders must be placed in quantities of 20. As with any alkaline cell, do not attempt to recharge it and recycle used cells responsibly.