The identity kit of the Master Control collection is a mix of technical rigour with stylistic restraint, drawing on inspiration from classic round timepieces made by Jaeger-Le Coultre in the 1950s. Not perhaps the sexiest name for a collection, JLC's Master Control refers to the fact that this collection was the first to undergo the brand's pioneering “1,000 Hour” control certification. Thirty years have passed since the introduction of the Master Control and two limited-edition models from the collection, the Master Control Date and Master Control Calendar, break away from the classic silver dials and appear with new blue faces.Two years ago, the Master Control collection underwent a subtle evolution to modernise the 40mm case of all its models with a thinner sloping bezel. More importantly, though, and in line with the technical focus of the collection, the Master Control was fitted with reworked and upgraded calibres boosting the power reserve from 38 to 70 hours. The only update to the Master Control Date and Calendar models is the incorporation of new blue dials; the case size, finishings and technical specifications remain unchanged. However, it's quite surprising what a difference the blue dial makes. Compared to the classic silver dials of former editions, the glossy blue dials give the watch a more contemporary, casual vibe.The Master control dateThe simplest model in the line-up is this classic time-and-date where the pure lines and no-nonsense design of the Master Control truly shine. Recalling the sober elegance of JLC's round 1950s models, the faceted dauphine hands and dart-shaped indices on the uncluttered dial capture the vintage spirit perfectly. Ad - Scroll to continue with article The silky blue sunray-brushed dial plays with the light, changing from light blue to darker blue depending on the angle. However, the silver-coloured faceted and applied indices and Arabic numerals at 12, 6 and 9 are a little lost against the blue background. To assist legibility, the minute track is depicted against a lighter blue background with white markings and the signature luminous dots at every hour. The faceted dauphine hour and minute hands also have a thin strip of lume down their spines. Matching the colour scheme of the minute track, the date window has a light blue background with white transferred numerals. In line with the aesthetic upgrades conducted on the Master Control line in 2020, the 40mm stainless steel case features a thinner, sloping bezel and the more pronounced curve of the bevelled lugs lets the watch sit closer on the wrist. The thickness of 8.78mm gives the watch a more elegant profile enhanced with its blend of brushed case flanks and polished bezel and lugs.Equipped with JLC's self-winding new-generation calibre 899 with a silicon escapement and a redesigned barrel to house a longer mainspring, the movement delivers a robust 70-hour power reserve. The sapphire caseback reveals the refined finishings, including the openworked gold rotor with thick C?tes de Geneve that are reproduced on the bridges and the circular graining on the base plate.The Master Control Date comes with a matching blue calfskin strap with blue stitching and a quick-change mechanism. It is a limited edition of 800 pieces, priced at EUR 9,100.Quick facts: 40mm x 8.78mm – stainless steel case – sapphire crystal front and caseback – 50m water-resistant – in-house, automatic calibre 899 (new generation) – 70h power reserve – 4Hz frequency – hours, minutes, seconds, date – blue calfskin strap with folding buckle – reference Q4018480 – EUR 9,100?– limited to 800 piecesThe Master Control CalendarThe particularity of this triple calendar is the jumping peripheral date hand that performs a leap from the 15th to the 16th of each month to ensure the moon phase display is not obscured. The well-balanced arrangement of the functions, with two rectangular apertures for the day of the week and month, the peripheral pointer date and the moon phase with seconds at 6 o'clock harks back to a 1940s JLC Triple Date Moonphase model.The 40mm stainless steel case responds to the design upgrade of 2020 and features a thinner bezel and bevelled, curved case lugs. Gleaming polished finishings on the bezel and lugs contrast with the brushed case flanks. With its more complicated movement, the case is slightly thicker with a height of 10.95mm and has two recessed pushers in the case band on either side of the crown and another on the left side of the case. These pushers are used to adjust the calendar and moon phase functions with the special tool provided. Again, the legibility of the blue sunray-brushed dial is enhanced with a light blue minutes scale with white markings and luminous hour dots and the faceted dauphine hour and minute hands are treated with a sliver of Super-LumiNova.A slender date hand with a red-lacquered tip extends to the peripheral date ring and makes a 90¡ãdegree jump between the 15th and 16th of every month. Two red arrows indicate the jumping date area, and the words QUANTIEMEa DATE SAUTANTE are printed in white to match the date numerals, save for the number 31, which is picked out in red to match the tip of the jumping date hand and the arrows.In keeping with the all-blue colour scheme, the day of the week and month apertures have blue backgrounds with white inscriptions. Even the moon phase aperture and the snailed small seconds track have been tinted blue.Like the calibre powering the date model, the automatic movement inside the Master Control Calendar was upgraded in 2020 with silicon parts. JLC's in-house calibre 866 is directly inspired by the brand's historical Triple Calendar timepieces but with 21st-century technology. The new barrel design delivers a robust power reserve of 70 hours. A sapphire caseback reveals the openworked gold rotor and the refined finishings of the movement.The Master Control Calendar comes with a matching blue calfskin strap with blue stitching and a quick-change mechanism. It is also a limited edition of 800 pieces, priced at EUR 13,700.Quick facts: 40mm x 10.95mm – stainless steel – sapphire crystal front and caseback – 50m water-resistant – in-house, automatic calibre 866 (new generation) – 70h power reserve – 4Hz frequency – hours, minutes, small seconds, triple calendar, moon phases – blue calfskin strap with folding buckle – reference Q4148480 –?EUR 13,700 –?limited edition of 800 piecesMore information at www.jaeger-lecoultre.com.