105mm M1 Artillery Shell Casing, TRENCH ART

The markings indicate it's an "AMM LOT LS-DZ-1366 CARTRIDGE M1," used with "HOW M2A1 M2A2 M103 M137 DUALGRAN".
The M101A1 was the standard U.S. light field howitzer during World War II and the Korean War, known for its accuracy and powerful punch.
This type of shell casing is often repurposed as "trench art" or as decorative items, like the one shown in the image.
The 105mm howitzer uses "semi-fixed" ammunition, where the projectile and cartridge case are loaded together, but the powder charge can be adjusted by separating them.
VERY COLLECTIBLE, EXCELLENT CONDITION,
SMOKE FREE HOME, PURCHASED FROM AN ESTATE OF VETERAN OF WWII, FAST AND SAFE SHIPPING, TRUSTED SELLER