This product is either discontinued or we cannot get that from suppliers.
Qnap Power Supply Unit For SP-8BAY-PSU, Output - 350 watts, Input - 100-240V AC, 47-63Hz, Compatible with TS-809 PRO/859 PRO/859 PRO /869 PRO.
The QNAP SP-8BAY-PSU 350W Power Supply Unit is an internal power supply which is specifically designed to work accurately with TS-809 PRO/859 PRO/859 PRO /869 PRO