Glass Beads provide the transition from a connector, through a housing wall, to a microcircuit. The K100 is designed to work with these K connectors: K102F, K102M, K103F, K103M, K104F, and the K104M. Anritsu also sells the K100B Glass Bead. The difference between the K100 and K100B is that only the V100B is specified to be hermetic. The K100 and K100B are dimensionally identical.