Mitsumi Tactile Switch
Type no. SOA 112HS
A pack of 25 tactile switches by Mitsumi. They are surface mount in style, with 4 connection pins, 2 either side of the 6mm body, button size is 4.3mm.
The switch is itself designed to be mounted flat on the PCB with the button pointing upwards.
They are also available in larger quantities packed in original sealed bags of 500, and outer boxes of 1000.