Spin Button

A two-segment UI control increases or decreases the numeric value in a field incrementally.

Use descriptive labels

With very few exceptions, labels should always be used with a text field. The label itself should also be descriptive and clear in its meaning.

Do
Numerical input field labeled 'Maximum'.

Be specific and descriptive of the type of data being requested. In this case, it is the name of a value.

Don't
Numerical input field labeled 'Number'.

Unless your context is very clear, avoid generic labels that can be open to interpretation.

Step buttons must increment values consistently

Do
Numerical input field with option '10'.

The step buttons must increase/decrease the value by the same amount that is configured. In the example above, increments are by 5.

Don't
Numerical input field with option '4'.

In this example, the step buttons increase the value by increments of 5 but decrease the value by incrementing one.