5.5mm x 2.1mm DC Power Plug to Screw Terminal AdapterAdapts wire leads to coaxial/barrel DC power connector.Screw Terminals to 5.5mm O.D. x 2.1mm I.D. DC Power Plug.Features:DC 5.5mm x 2.1mm plug with marked polarity for the solderless set screw terminals.Center is Positive.Ideal for CCTV security cameras. No more soldering. A small screw driver is all you need to connect you power leads.19452 PL