Great 4 AA battery holder for your Arduino project! These are great for replacements for electronic devices that have a lost or damaged battery holder. Provides 6V output when used Alkaline batteries, 4.8V when used with rechargeable AA. These AA battery holders feature a standard snap connector on one end. The case is made from ABS plastic with nickel plated springs to hold your AA batteries in place. Each battery holder measures 2 7/16" x 2 3/8" x 5/8"( L * W * H ). AA batteries in these holders will last much longer than a standard 9V battery will when powering up electronic projects. AA batteries not included. For use in SentrySafe models that begin with A3, A4, A5; J3, J4, J5; S0, S3, S4, S5, S6, S7, S8, SB, SBW, SC, SW; J3, J4, J5; L0, L3; V: Replaces Sentry Safe part number BP4AA. Also for use with the Schlage Connect Deadbolt devices. This is also a direct replacement for the Delta Faucet battery pack part number RP30532.