An input/output, I/O, device, comprising: a base portion configured to physically and communicatively connect the I/O device with at least one other device via electrical contacts and via base connection features; an I/O module physically and communicatively connected to the base portion for delivering and receiving input/output to and from field devices and communicating inputs/output to control/monitoring devices via the base portion and comprising I/O communication circuitry and a terminal block mount surface; and a terminal block physically and communicatively connected to the terminal block mount surface of the I/O module, wherein the terminal block mount surface comprises a plurality of connectors for coupling with respective connectors of the terminal block; wherein the terminal block mount surface has a width that is greater than a corresponding width of the terminal block such that a portion of the terminal block mount surface extends beyond the terminal block, said portion of the terminal block mount surface extending beyond the terminal block including at least one vent for permitting the flow of air through the I/O module and along the terminal block and providing, that, in case that a plurality of I/O devices is mounted on a rail in abutting engagement with each other, an air gap is formed between terminal blocks of respective adjacent I/O devices, wherein the terminal block mount surface of the I/O module is an upper surface of the I/O module, and wherein an opposing bottom surface of the I/O module is engaged with the base portion, the I/O module further comprising at least one vent (Vi, Vo) on a front and/or a back surface of the I/O module, the front and back surfaces extending between the upper surface and the bottom surface of the I/O module. a base portion configured to physically and communicatively connect the I/O device with at least one other device via electrical contacts and via base connection features; an I/O module physically and communicatively connected to the base portion for delivering and receiving input/output to and from field devices and communicating inputs/output to control/monitoring devices via the base portion and comprising I/O communication circuitry and a terminal block mount surface; and a terminal block physically and communicatively connected to the terminal block mount surface of the I/O module, wherein the terminal block mount surface comprises a plurality of connectors for coupling with respective connectors of the terminal block; wherein the terminal block mount surface has a width that is greater than a corresponding width of the terminal block such that a portion of the terminal block mount surface extends beyond the terminal block, said portion of the terminal block mount surface extending beyond the terminal block including at least one vent for permitting the flow of air through the I/O module and along the terminal block and providing, that, in case that a plurality of I/O devices is mounted on a rail in abutting engagement with each other, an air gap is formed between terminal blocks of respective adjacent I/O devices, wherein the terminal block mount surface of the I/O module is an upper surface of the I/O module, and wherein an opposing bottom surface of the I/O module is engaged with the base portion, the I/O module further comprising at least one vent (Vi, Vo) on a front and/or a back surface of the I/O module, the front and back surfaces extending between the upper surface and the bottom surface of the I/O module.