I’ll assume this phrase refers to a custom, high-quality digital asset or media package created by or for “1st Studio” (or “1st Studio Siberian”), centered on a “Siberian mouse” concept — perhaps a stylized 3D character or prop — delivered in MSH (mesh) format and an AVI (video) preview at 45 frames per second, labeled “extra quality.” Below is a comprehensive, polished article describing such an asset: its concept, design process, technical specifications, artistic rationale, use cases, optimization and quality considerations, and distribution and licensing notes.