This is German World War I Model stick grenade, designed to be easily incorporated into your scenes known as Stielhandgranate.

This example is a winter variation.

Introduced in 1915 during World War I, the German stick grenade evolved through several design changes over the years. Known for its distinctive shape, the Stielhandgranate also employed a friction-based igniter, a mechanism uncommon in most other countries but widely used in German grenades.

Materials: PBR metallic/roughness workflow to achieve physically accurate result.

The model meets all requirements.