50 Years Compass Perpetual Calendar Best for unique gift for someone else or self too. This compass perpetual calendar key chain, key ring is very creatively designed and fantastically crafted. Adelicate perpetual calendar, also a great key chain decoration. Made of solid alloy, can bear long lasting using. This compass 50 years perpetual calendar key chain, key ring is great gift for yourself or others. A compass perpetual calendar key chain, key ring. A great perpetual calendar, also a greatkey chain ring decoration, Characters on the compass are colour filling in the groove, not easy to fade or to abrade with a shining mirror on the back. A small pushing handle on the compass for turning Great for oneself or as a gift toothers. Zinc alloy - Material. Ring diameter: Approx. 1.26 inch/3.2 cm Compass (D x T): Approx. 1.69 x 0.16 inch/4.3 x 0.4 cm. To use turn the upper disc, aligning the year andmonth you are to seek, then the diagonal direction will show you the week information of each day in the month, You can know the week of every day in the range of 2007-2056 black S means saturday and red S means sunday. When you seek for January or February in a leap year, you should aligning with the red JAN and FEB.