A system for delivering tumor treating fields, TTFields, to a body of a subject, the system comprising: an electric field generator configured to generate an electrical signal having an alternating current waveform at a frequency in a range from 50 kHz to 500 kHz; a first conductive lead (58; 58a) electrically coupled to the electric field generator, the first conductive lead (58; 58a) being configured to carry the electrical signal; a first pad (70; 70a; 70c; 70d; 70e) coupled to the first conductive lead (58; 58a), the first pad (70; 70a; 70c; 70d; 70e) having a foam and a first conductive gel element; a second conductive lead (58; 58b) electrically coupled to the electric field generator, the second conductive lead (58; 58b) being configured to carry the electrical signal; and a second pad (70; 70b; 70c; 70d; 70e) coupled to the second conductive lead (58; 58b), the second pad (70; 70b; 70c; 70d; 70e) having an electrode element (104; 136) and receiving the electrical signal from the second conductive lead (58; 58b), the electrode element (104; 136) being connected to a second conductive gel element; characterised by: the foam being a conductive foam and receiving the electrical signal from the first conductive lead (58; 58a); the conductive foam having a solid continuous phase material being at least one of constructed of a conductive material or having a conductive material attached, absorbed or adsorbed to the solid continuous phase material and defining a plurality of pockets (240; 240a-d) interspersed throughout the solid continuous phase material; and the first conductive gel element being attached, absorbed or adsorbed to the conductive foam. an electric field generator configured to generate an electrical signal having an alternating current waveform at a frequency in a range from 50 kHz to 500 kHz; a first conductive lead (58; 58a) electrically coupled to the electric field generator, the first conductive lead (58; 58a) being configured to carry the electrical signal; a first pad (70; 70a; 70c; 70d; 70e) coupled to the first conductive lead (58; 58a), the first pad (70; 70a; 70c; 70d; 70e) having a foam and a first conductive gel element; a second conductive lead (58; 58b) electrically coupled to the electric field generator, the second conductive lead (58; 58b) being configured to carry the electrical signal; and a second pad (70; 70b; 70c; 70d; 70e) coupled to the second conductive lead (58; 58b), the second pad (70; 70b; 70c; 70d; 70e) having an electrode element (104; 136) and receiving the electrical signal from the second conductive lead (58; 58b), the electrode element (104; 136) being connected to a second conductive gel element; characterised by: the foam being a conductive foam and receiving the electrical signal from the first conductive lead (58; 58a); the conductive foam having a solid continuous phase material being at least one of constructed of a conductive material or having a conductive material attached, absorbed or adsorbed to the solid continuous phase material and defining a plurality of pockets (240; 240a-d) interspersed throughout the solid continuous phase material; and the first conductive gel element being attached, absorbed or adsorbed to the conductive foam. the foam being a conductive foam and receiving the electrical signal from the first conductive lead (58; 58a); the conductive foam having a solid continuous phase material being at least one of constructed of a conductive material or having a conductive material attached, absorbed or adsorbed to the solid continuous phase material and defining a plurality of pockets (240; 240a-d) interspersed throughout the solid continuous phase material; and the first conductive gel element being attached, absorbed or adsorbed to the conductive foam.