Color: Blue - Material: PCB + metal - The real time clock has the ability of calculating prior to the 2100 seconds points when Japan week month year and the ability to adjust a leap year - 31 8-bit RAM - Wide working voltage: 2.0~5.5 V - When The working voltage is 2.0V the current is less than 300nA - Read/write clock or RAM data have two transmission way: Single-byte / many bytes group - 8 feet DIP assembly or optional 8 feet SOIC encapsulation according to surface assembly - Simple 3 line interface - Compatible with TTL Vcc=5V - Double main and backup power supplies - Power LED indicator - Packing list: - 1 x DS1302 real time clock module - 1 x CR1220 battery - 1 x Dupont cable (21cm)