"Yue sao" typically are live-in domestic helpers who care for both the new mother and baby for the first month after birth. Salaries as at 2017 vary from RMB8000 to RMB20000 per month depending on city and experience. They are described as "mothering the mother". Australian documentary-maker Aela Callan called them "Chinese supermums" but says they are colloquially known as "confinement ladies". Companies have sprung up to offer extended postpartum care outside the home, sometimes in a hotel-like environment. Luxury options are a business. Private postpartum care centres were introduced to Korea in 1996 under the name of "sanhujoriwon". Within the Chinese tradition, specialist businesses such as Red Wall Confinement Centre charge up to $27,000 for one month. In Taiwan, postpartum nursing centres are popular, for those who can afford them. Birth tourism centres operating under the radar in the United States for Chinese women offer "sitting the month".