Inhibits voltage-gated sodium channels Nav1.1/SCN1A (IC(50)=630 nM), Nav1.2/SCN2A (IC(50)=230 nM), Nav1.3/SCN3A (IC(50)=770 nM), Nav1.4/SCN4A (IC(50)=1290 nM), Nav1.6/SCN8A (IC(50)=630 nM), Nav1.7/SCN9A (IC(50)=15.3-1000 nM) and potassium channels Kv11.1/KCNH2 (IC(50)=4.2 uM). Expressed by the venom gland. The presence of a 'disulfide through disulfide knot' structurally defines this protein as a knottin. This toxin does not inhibit sodium channels Nav1.5/SCN5A (IC(50)=22 uM) and potassium channels Kv11.2/KCNH6, Kv11.3/KCNH7, Kv1.1/KCNA1 and Kv1.4/KCNA4 (IC(50)>200 uM). Belongs to the neurotoxin 30 (phrixotoxin) family.