This tribe is originally from Myanmar (Burma), but due to the army rule in their country and due to the fact that they were struggling to make a living, they migrated to neighboring Thailand. Here, they live as refugees in the north west border of Thailand. They eke out a living by doing odd manual labor jobs and by doing some basic agriculture where possible.
They are the Karen tribe of Burma and they are famous for their women and their long necks. The Karen men look like normal people donning normal clothes and doing normal jobs. But, their women use brass rings to elongate their necks. This is a very rare sight and these women use these heavy (some of them are 4-6 kilograms) brass rings because they believe that the longer their neck, the prettier they look.
Some years back, a lot of tribal women used to wear these rings, but these days, only a very few wear it to generate some income from the tourists who come to see them. Today, these tribal women have understood that long necks also mean frail necks and have stopped their girl children from continuing the tradition. Instead, they try and give them regular education.
If you are in Thailand and wish to see them in person, head to some of the villages to the north of Mae Hong Son in Northern Thailand. Many of these villages along the Myanmar border are long necked Karen villages and offer facilities for tourists to interact with these women. I went to Baan Noi Soi village to see these tribal women and had to pay 200 THB to explore their village, talk to the women and take their photographs. This money is used to supplement the income of this village and is spent in getting food supplies and reading material.
If you wish to help this community a bit more, then you can buy some of the handicrafts made by them. These handicrafts include hand woven cotton scarves, long necked Karen statues as souvenirs and other interesting handicrafts.