“Thai Tabs” (also known as “Ya-Ba” tablets) usually contain 10 - 20 percent d-methamphetamine HCl and 80 - 90 percent caffeine. The tablets in this case had an average tablet weight of 103 milligrams, a diameter of 6.05 millimeters, a width of 3 millimeters, and were otherwise unremarkable. anyone heard of these new pills are they good because i lokked and they only containg 10mg or meth and like 100mg of caffeine will i fell effects with that little of meth