LCD Talking Keychain (630-0910) Specifications Faxback Doc. # 7097 Alarm Clock Power Source:...........................Two 357 type Button-Cell Batteries (such as Radio Shack Cat. No. 23-105). Accuracy:.................................................+/- 0.67 Sec/Day Dimensions:..................................2 5/16 x 1 7/16 x 9/16" (HWD) Weight:.....................................................1.23 oz (35 g) Battery Life:...............................................About one year (smc-03/01/94)