此為高低壓調整螺絲(調上為低壓，下為高壓)

此為高低壓調整螺絲
(調上為低壓，下為高壓)

Kết quả (Anh) 1:

Why high and low pressure adjust nut hex(Why low pressure on Zambia, because under high pressure)

Kết quả (Anh) 2:

This is the high and low pressure adjustment screw
(the tone for the low-voltage, under high pressure)

Kết quả (Anh) 3:

This is a high and low pressure adjustment screw(adjust for low pressure, lower for high pressure)