is there a class for buffer storage? maybe like ArrayList?

Question

Hi. Say I'm building a ZIP file, the ZIP file has a header of UInt32 0x04034b50 then some 2-byte tags, short 0x0A00, and another short. How can i save these: uint part1=0x04034b50; ushort part2=0x0a00; ushort part3=0; I can't put then into an ArrayList because they are of different type. In the end I want to extract the arraylist and put into a byte[].