看起來很不錯，價格也很好，
http://www.costco.com/Browse/Product.aspx?Prodid=11645558&search=spa%20sonic&topnav=&Mo=0&cm_re=1_en-_-Top_Left_Nav-_-Top_search&lang=en-US&Nr=P_CatalogName:BC&N=5000043&whse=BC&Dx=mode%20matchallpartial&Ntk=Text_Search&Dr=P_CatalogName:BC&Ne=4000000&D=spa%20sonic&Ntt=spa%20sonic&No=0&Nty=1&Ntx=mode%20matchallpartial
