Spectrum Chemical manufactures and distributes fine chemicals with quality you can count on including those with CAS number 1634-04-4, Whether you call it Methyl tert-Butyl Ether, MTBE or tert-Butyl Methyl Ether you can be assured the Methyl tert-Butyl Ether products offered by Spectrum, meet or exceed the grade requirements or specifications for each individual product.