I use 2 of these. They are good out to about 100 meters. You can get one that’s up to 60W for another 20 bucks. But I find 30W will run around 4 to 6 cameras.
Cudy POE200 30W Gigabit PoE Injector Adapter, 30W,10/100/1000Mbps RJ-45, IEEE 802.3af / 802.3at Compliant, up to 100 Meters (325 Feet) Amazon.com