This is an evolved "MK4" flight jacket, the successor to the Royal Air Force (RAF) masterpiece MK3. Size: 7 (Shoulder width 50cm, Body width 64cm, Length 64cm, Sleeve length 65cm) Around 2010, the MK3 was improved and succeeded by the new MK4. The outer shell fabric was changed to 'GORE-TEX'. This dramatically enhanced the waterproof/water-repellent and cold-weather protection, resulting in a significant evolution. The distinctive large collar has a chin strap, which can be fastened to prevent wind from entering. The front has a double closure with a zip and buttons, and the fly front completely covers the zip to shut out the wind. The large-capacity "slash zip pockets" located on the abdomen are easily accessible and combine practicality and design. The left sleeve is equipped with a padded "utility pocket" (pen holder). The cuffs are adjustable with Velcro to prevent wind from entering. A "stowable hood" is also included under the collar on the back, which can completely cover the neck like an anorak. The hood also uses Gore-Tex. A so-called "beaver tail" with Velcro closure is attached to the lower part of the inside of the back. This is used to prevent flapping during parachute descent, and is taken out from the back and passed to the front for wearing. All buttons use "parachute buttons." These buttons were developed by the military to prevent the buttons from catching on parachutes during descent. They do not use thread, so there is no risk of entanglement, and they are designed for easy removal. As you can see, this jacket has a high-spec construction that refines practicality. The use of Gore-Tex in the fabric makes its functional beauty the highest peak. The sizing is a short length, typical of flight jackets. This is to allow for ease of movement so that the hem does not interfere when seated in the cockpit. This length provides ample body width while cleverly suppressing the clumsiness of military wear. This refined size balance is one of the reasons why this jacket is so popular. It is a very popular and rare model. If you were looking for one, please consider it.