How can I power a POE camera with 12vdc?

VCS-4P1 & VCS-8P2 Camswitch Plus

They are compact, versatile POE switches powered by 12VDC or 24VDC allowing you to power cameras with POE. CAMSWITCH Plus is also available in 4+1 (VCS-4P1) and 8 + 2 (VCS-8P2) models.

In short: Enables you to install standard POE cameras where 12VDC is available, for example in a vehicle.