The Platinum Tools pocket-size PoE Detector detects PoE endmid-span voltages on network cables LED indicators instantly show ""GONO-GO"" detection on PoE networks Plug cables directly into the builtin RJ45 jack or use the included patch card to detect voltage in wall jacks Differentiates between end-span PoE power which is supplied from PoE switches or router and mid-span voltage from injectors End-span detection indicate voltages are found on pairs 12 36; mid-span detection indicates voltages found on pairs 45 78 GoNo-Go PoE Voltage Detector End-span or Mid-span Bright LED indicators Plug direct or use included patch cord Pocket-size 8023af or 8023at compatible Detection range is between 24V-48V