Artisan Power Polycom SpectraLink 8400 Phones: Clear Silicone Gel Case: 2310-37180-001 Fits Polycom/SpectraLink 8400, 8440, 8450 and 8452 Phones. Clear Gel Case made from Healthcare Grade Silicone. Plastic Ratchet Swivel Belt Clip. Matches OEM Part Number 2310-37180-001 Manufactured by Artisan Power, a leader in high quality replacement products.