M4A1-S | Leaded Glass by de puiseau appeared in CS:GO on September 14, 2017. It’s contained in the Spectrum 2 Case that was added to the shooter in the “China, are you ready?” update, timed to coincide with the launch of CS:GO in China through Valve's partnership with the publisher of Perfect World.

Most of the carbine's surface is covered with multicolored shards of leaded glass of varying shapes and sizes, some of which shimmer with several colors.

Float Value of M4A1-S | Leaded Glass can vary between 0.00 and 0.70, allowing the skin to be obtainable in any exterior quality category. As the weapon wears down, it doesn't lose paint but instead gets covered with a dark patina, noticeable in the “Battle-Scarred” exterior quality.

M4A1-S | Leaded Glass belongs to the “Classified” rarity grade and is available with the StatTrak kill counter. The skin is popular among CS2 players.