Potent, non-peptide KV1.3 channel antagonist that preferentially binds to the C-type inactivated state of the channel (IC50 ~ 200 nM) . Inhibits KV1.4 with an IC50 of ~ 300 nM. Selective over KV1.1, KV1.2, KV1.5, KV1.6, KV3.1-4, and KV4.2.