Classic Aviator Watch Citizen 51-1811 A true "tool" watch for pilots, this automatic Citizen 51-1811 is highly useful for all kinds of calculations. The case is quite large, measuring 43 mm excluding the crowns. It is made entirely of stainless steel. The front of the case is brushed with a circular pattern, while the rest is polished. The crown is for adjusting the inner bezel at 3 o'clock, and the winding crown at 2 o'clock. As seen in the picture, the case integrates and protects the lugs and double crowns. The main attraction of the watch is its dial. It is designed in grey with a sunburst effect. On the outside, there is a gold ring with black numerals. The gold ring is surrounded by a thin red area that separates the dial from the gold rotating bezel. The entire face of the watch is bright and strong. In the grey area, there is the Citizen logo, the white painted "automatic 21 jewels" lettering, the day and date (in a single gold bezel), and luminous hour markers. This type of inner frame is called a sliding ruler. How does it work? In short, it's used for multiplication, division, distance and volume conversions, time calculations, and percentages. The movement is the well-known Citizen 8200A caliber. It's an automatic movement (can also be wound manually) that operates at 21,600 beats per hour and features quick day and date adjustment. It has a unidirectional winding rotor and 21 jewels. The bracelet is made of stainless steel with a polished center and brushed edges. It beautifully complements the overall polished design of the watch. It features folded "H" shaped links and a signature "Citizen" buckle. Our watch has undergone all necessary maintenance. The pictures are our own and show all the details. The pictures are part of the description, please review them. Remember that customs duties are the buyer's responsibility. Delivery within 3-5 days via DHL.