Aluminum electrolytic capacitors use an electrolytic process to form the dielectric. Wet electrolytic capacitors have a moist electrolyte. Dry or solid electrolytic capacitors do not. There are two basic configurations or form factors for aluminum electrolytic capacitors: leaded and surface mount. There are also several different mounting styles. Leaded capacitors have leads for connections to circuits. They use through hole technology (THT) to mounts component on a printed circuit board (PCB) by inserting component leads through holes in the board and then soldering the leads in place on the opposite side of the board. Surface mount capacitors or chip capacitors do not have leads or use THT. Instead, SMT capacitors have a flat surface that is soldered to a flat pad on the face of the PCB. Mounting styles for aluminum electrolytic capacitors may also use bolts, brackets, and poles.