The Old Guard, the soldiers assigned to guard the Tomb of the Unknown Soldier, carrying the new ceremonial M17 pistol.

From the Sig Sauer website:

• Pistol Names: each of the four pistols bears the name of Silence, Respect, Dignity, or Perseverance and is featured on the dust cover. Dignity and Perseverance represent “The Sentinel’s Creed,” and Silence and Respect represent the request to the public by Arlington National Cemetery when visiting the Tomb of the Unknown, and during the Changing of the Guard;
• Custom Wood Grips: in 1921 the chosen Unknown was transported to the United States of America aboard the USS Olympia. The custom wood grips are made with wood from the USS Olympia and include the crest of the 3rd Guard, Tomb of the Unknown Soldier identification badge inset;
• Cocking Serrations: XXI cocking serrations are engraved on the slide to signify the twenty-one steps it takes for the Tomb Sentinels to walk by the Tomb of the Unknowns and the military honor of a 21 Gun Salute;
• Sight Plate: an engraved impression of the Greek Figures featured on the east panel of the Tomb – Peace, Victory, and Valor – are featured on the sight plate;
• Sights: a glass insert made with marble dust from the Tomb of the Unknown fills the sights of the ceremonial pistols;
• Engraved Magazines: the 21-round magazines feature an aluminum base plate engraved with the names of the Greek figures featured on the Tomb of the Unknown – Peace, Victory, and Valor – and include a name plate on the bottom of the magazine engraved with the Tomb Sentinel badge number.
• Serial Numbers: the pistols are serialized with a unique set of serial numbers that incorporate items of significance to the Old Guard: “LS” represents line six of the Sentinels’ Creed, “My standard will remain perfection; “02JUL37” to signify the first 24-hour guard posted at the Tomb of the Unknown on July 3, 1937; “21” to signify the 21 steps it takes the Tomb Sentinels to walk by the Tomb of the Unknown, and the military honor of a 21 Gun Salute. The full series of M17 Tomb of the Unknown Soldier Pistols serial numbers are LS02JUL37A21 (Silence), LS02JUL37B21 (Respect), LS02JUL37C21 (Dignity), LS02JUL37D21 (Perseverance).

I did not know you could polish Kydex that shiny.