Two different types of dual-polarized battery contacts have been developed offering left and right configurations to achieve the desired polarity. The Part #5214 is built using a coil spring negative contact and a button-type positive and can be used with AAA, AAAA and N batteries. They also have been designed for use in molded cases or self-contained battery compartments. The Part #5213 is designed to clip on to 0.06" through 0.07" thick panels. It features sharp barbs that securely anchor contacts in place. Manufactured using 0.012" thick, nickel-plated spring steel, both the leaf spring negative contact and a button-type positive are said to create reliable spring tension to properly hold A and AA batteries to achieve low contact resistance.