Lost power supply for DVR, any alternative?

Lost my power supply strip for the dvr, It calls for DC12v 4a, Can I use DC12V 5a or is it a concern?

You can use a 5A no problems. Its like having a 5 gallon tank on your motorbike instead of a 4 gallom tank.

If it's not too late for you,

4A is the minimum current the PSU needs to deliver, so anything above 4A is fine.

Ensure that the adapter is the correct polarity. Nearly all DVRs require centre positive, but not all PSUs are.

Coaxial power plugs come in two sizes of inner pin, either 2.1mm or 2.5mm. This needs to be correct.