You can use the ZINC AIR PR312 batteries in these types of hearing aids:mini BTE (behind-the-ear)RITE (receiver-in-the-ear)ITC (in-the-canal)Before putting the batteries in the hearing aid, wait at least 30 seconds. A ZINC AIR battery that has not been used yet, has a sticker on the backside for closing off the battery. The battery is not activated until the sticker is removed. When you remove the sticker, air can flow into the battery and automatically the battery will be activated. Also before closing the battery compartment of the hearing aid, wait at least 30 seconds up to 1 minute to let the battery breath. When you do this, the lifetime of the battery can be prolonged extensivelyPanasonic PR312 brown hearing aid batteries have a size 312 and 7.9mm x 3.6mm. These batteries are ideal for BTE (behind the ear), ITE (in the ear) and RITE (receiver in the ear) hearing aids. The batteries have an average lifespan of 3 to 10 days.Ideal for new generation digital hearing aids, Reliable power in various temperature conditions, Comfortable, light and providing a steady level of power, No mercury added