Potent and selective inhibitor of Kv1.2/KCNA2 potassium channels. Expressed by the venom gland. Has the structural arrangement of an alpha-helix connected to antiparallel beta-sheets by disulfide bonds (CS-alpha/beta). Does not block Kv1.1/KCNA1 and Kv1.3/KCNA3 potassium channels. Belongs to the short scorpion toxin superfamily. Potassium channel inhibitor family. Alpha-KTx 13 subfamily.