The MikroTik RB951G-2HnD is a wireless router that generally uses an external power supply. The key specifications for the power supply of this model are as follows:

• Input voltage: 8-30V DC. This allows some flexibility in the type of power adapter that can be used, although it is common to use one within the 12V to 24V range.
• Current: An adapter of at least 1A (1000 mA) is generally recommended to ensure proper and stable operation of the device. MikroTik usually includes a 12V 1A adapter with this model.
• Connector: The RB951G-2HnD uses a standard barrel connector, with a common size of 2.1mm x 5.5mm.

When looking for a replacement or additional power supply for your MikroTik RB951G-2HnD, make sure it meets these parameters. It is advisable to use a MikroTik power adapter or a third-party equivalent that meets the mentioned specifications to avoid any compatibility issues or damage to the device.