Sennheiser Polycom Adapter Cable for Electronic Hook Switch for Soundpoint IP 430 and Above Polycom adapter cable for Electronic Hook Switch for Sound point IP 430 and above. Suitable for DW Office, DW Pro 1, DW Pro 1 ml, DW Pro 1 Phone, DW Pro 2, DW Pro 2 ml, DW Pro 2 Phone, Also suitable for SD Office, SD Office ml, SD Pro 1, SD Pro 1 ml, SD Pro 2, SD Pro 2 ml and D 10 Phone