Two crystals for time keeping purposes counters etc. using simple flip-flop divider stages. One crystal generates 1 Hz & one generates 50 Hz when divided by 2n. The 32.768k Hz crystal is suitable for use as a replacement in most digital watches & the crystal for generating 50 Hz can be used to drive mains operated clocks from a battery when mains fails or in portable applications. Frequency Application 32.768k Hz Divide by 2n 15 times for 1 Hzdigital watch crystal 3.2768 M Hz Divide by 2n 16 times for 50 Hz Freq Can Adjust Temp Load Style Tol Stability Cap 32.768k Hz TC38plusmn 15ppmplusmn 15ppm 12.5p F3.2768 M Hz HC-49 Uplusmn 30ppmplusmn 30ppm 12p F The crystals have a temparature range of -10 C to 60 C.