Thailand medical revenue stamp.
แสตมป์บริษัท The SERMMITR CO.,LTD
ป้ายฉลากยาตราสามธง ของบริษัท The SERMMITR CO.,LTD

Printed to seal packages of pharmacy products to prevent counterfeiting.
the red seals are 3 different shades of 3 different printings.
The green seal has perfins “TDL Specimen”. The text in Thai blow the printings states that the seal should be present to guarantee the original product.