Potassium channel modulating agents of Formula Ia or Ib and enantiomers and mixtures enantiomers and N-oxides thereof, and pharmaceutically acceptable salts thereof, and their use in the preparation of pharmaceutical compositions. Also, pharmaceutical compositions useful for the treatment or alleviation of diseases or disorders associated with the activity of potassium channels, e.g., respiratory diseases, epilepsy, convulsions, vascular spasms, coronary artery spasms, renal disorders, polycystic kidney disease, bladder spasms, urinary incontinence, bladder outflow obstruction, irritable bowel syndrome, gastrointestinal dysfunction, secretory diarrhoea, ischaemia, cerebral ischaemia, ischaemic heart disease, angina pectoris, coronary heart disease, traumatic brain injury, psychosis, schizophrenia, anxiety, depression, dementia, memory and attention deficits, Alzheimer's disease, dysmenorrhea, narcolepsy, Reynaud's disease, intermittent claudication, Sjorgren's syndrome, migraine, arrhythmia, hypertension, absence seizures, myotonic muscle dystrophia, xerostomi, diabetes type II, hyperinsulinemia, premature labor, baldness, cancer, immune suppression, or pain.