Aeroline bus departed from 3 places :1) Corus Hotel, KL (near KLCC); 2) Bandar Utama; 3) Bandar Sunway. They have buses departing in morning and afternoon, all details in the web site. The bus does not stop at Butterworth. it arrives in Penang . There are 2 stops, 1st stop at Queensbay, 2nd stop at Sungai Nibong Bus Terminal (10 mins away). If you intend to take taxi to your destination, suggest to stop at Sungai Nobong Bus Terminal. Aeroline normally takes 4.5 hours to 5 hours for the whole journey with 1 stop half way. The bus do have a toilet on board for small release ONLY. They do provide a drink and snack on board. If you are taking bus from Corus Hotel, can enjoy a complimentary coffee at the hotel coffee house - https://12go.asia/en/travel/kuala-lumpur/penang