The Rolex Oyster Perpetual 31 reference 277200 (including the lavender dial variant) is built on the robust Oyster architecture, designed for durability and water resistance. 

• Case Diameter: 31 mm

• Case Material: Oystersteel (Rolex’s proprietary 904L stainless steel)

• Bezel: Smooth, domed Oystersteel

• Crystal: Scratch-resistant sapphire

• Crown: Screw-down with Twinlock double waterproofness system

• Water Resistance: 100 meters (330 feet)

• Bracelet: Oystersteel Oyster bracelet with three-piece solid links

• Clasp: Folding Oysterclasp with Easylink 5 mm comfort extension link

• Lug Width: 16 mm

• Case Height: Approximately 10.65 mm 

The Rolex Oyster Perpetual 31 reference 277200 is powered by the Calibre 2232, a self-winding mechanical movement developed and manufactured entirely by Rolex. 

Core Performance Specifications The movement operates at a frequency of 28,800 vibrations per hour (4 Hz) and utilizes 31 jewels to reduce friction.  It provides a power reserve of approximately 55 hours when fully wound.  Rolex certifies this caliber as a Superlative Chronometer, guaranteeing a precision of -2/+2 seconds per day after casing, which exceeds standard COSC requirements.  The movement features a bidirectional self-winding system via a Perpetual rotor and includes a stop-seconds mechanism for precise time setting.