The optocouplers are available in all possible soldering landing patterns. The DIP-4 package is offered with five different leadframe options for customer designs. The housing of the optocoupler is the same, but the products differ in leadframe. Two through-hole (THT) products called standard and M-type are offered. The main difference is the clearance. Through-hole products are connected and soldered through the PCB. The next three DIP-4 packages featured are the surface-mount (SMT) product types. The two closed products are S- and SL-type. These products feature the same footprint, but the total height of the products is the key parameter difference. The last surface-mount type is the SLM which is characterized by a wide clearance. The surface-mount products can be soldered on the PCB.