Twenty-four x size 10 (yellow) Mercury Free Hearing Aid Batteries. Rayovac, the world"s longest lasting mercury free hearing aid battery. Performance equal to that of standard (mercury containing) hearing aid batteries. New advanced voltage formula. Convenient dial turns to easily dispense batteries, while a door on the rear protects the batteries from damage when not needed. Perforated card allows you to tear off bottom dial for portability and compact storage. All batteries are tabbed for easy use. Quality and performance guaranteed. Made in the USA. Rayovac, the global leader in Mercury Free Hearing Aid Batteries is the #1 choice of Audiologists and the longest lasting mercury free hearing aid battery in the world. Our new design eliminated mercury from the cell while maintain performance equal to that of standard hearing aid batteries. Additionally, Rayovac"s Mercury Free formula delivers up to 30 percent more battery life than other mercury free hearing aid batteries. Rayovac is a division of Spectrum Brands Holdings, Inc. a global consumer products company and a leading supplier of batteries, shaving and grooming products, personal care products, small household appliances, specialty pet supplies, lawn & garden and home pest control products, personal insect repellents and portable lighting.