This is a DB9 female/male adapter plate signal module, RS232 Serial DB9 9-pin to 9 Position Screw Terminal Block. Connector DB9 adapter terminals to facilitate commissioning equipment of project. The wire range of the 9 Positions Screw Terminal Block is 22-14AWG. All-copper DB9 Socket, anti-oxidation, contact better. Terminal pitch is 3.96mm, screw hole diameter is 2mm, need to use a slotted screwdriver width 2mm be removable.