Blocker for the small conductance calcium-activated potassium channels (PubMed:8385026, PubMed:8457543, PubMed:11527975). Shows similar affinities for KCa2.2/KCNN2 (Kd=22 nM) and KCa2.3/KCNN3 (Kd=25 nM) (PubMed:11527975). Expressed by the venom gland. Has the structural arrangement of an alpha-helix connected to a beta-sheet by disulfide bonds (CSalpha/beta). Belongs to the short scorpion toxin superfamily. Potassium channel inhibitor family. Alpha-KTx 05 subfamily.