An important aspect to consider when selecting your dip switch, is the solder process that the dip switch will be exposed to. CTS DIP switches come with an optional epoxy seal on the bottom, and an optional top tape seal. These two options should be considered, especially when the part will be exposed to post soldering board washing. The 209, 210, 218 and 219 Series are ultrasonically welded which eliminates the need for the bottom epoxy seal, but the bottom seal is listed as a standard feature.