Stimuli are signals that trigger the senses. Receptors detect the stimuli and neurons send the signals to the brain where they're interpreted. Each sense organ includes receptors that capture relevant stimuli for transmission to the brain. The receptors in the skin are mechanoreceptors and thermoreceptors.
AWWA Butterfly valves are quick opening valves that consist of a metal circular disc or vane with its pivot axes at right angles to the direction of flow in the pipe, which when rotated on a shaft, seals against seats in the valve body. They are normally used as throttling valves to control flow.
This clasp is often called a hidden clasp because when the watch band is closed the only portions of the clasp that show are the buttons. Because of this invisible clasp, the butterfly clasp is a very popular watch band clasp. Butterfly clasps are great for metal watch bands. The clasp is attached to the band by a tube with pins on each side of the band. The push buttons add an extra level of security to this watch band because the clasp cannot open until the buttons have been pushed in. To determine the size clasp that you need, you measure the tube length.