Over 20 years now I am studying Thai Buddhism and especially about the spirits and beliefs in buddha amulets (thai buddha amulets) which have been blessed from respected monks.
It is not necessary to mention that over all the belief in the power and spirit in genuine amulets in the Thai society (a small percentage of Thai's are not Buddhists) is very strong.
So there is nearly no Thai-buddhist found, who is not wearing at least one amulet and often in addition some other blessed Buddhist items (like one or several plakkiks or takruts) which should help in the daily life.
The history of Thai and Thai-Khmer Buddha amulets is very old and goes back to the Siam kingdoms of Sukhothai and Ayuttaya (Khmer art and culture, which have there roots in Hinduism, influenced these kingdoms very strong)