Two year multiple entry Business Visa

Hi I am an Irish citizen, living in Thailand and have to travel to China once a month. I note that your website states:2. Validity (enter before)
Validity shown as "enter before" refers to the time limit of visa. The holders must use the it to enter mainland of PRC before 24:00 on the exact day of expiration, otherwise, it expires after time limit and cannot be extended no matter whether there is number of entry left, and reapplication is required. The validity is 3 months, 6 months, one year and two years. It is suggested to check the validity to assure it is good to be used.
Where can I obtain a 2 year multi-entry Business M type? I have many double entry permits in my passport and I stay only a few days each time.