Primefaces keyFilter regular expression number with decimal 0 or 5

Question

I would like to use pe:keyFilter so that a user can enter a number with the decimal parts only containing 0 or 5. So, for example 6,5 or 7,0 are accepted but 6,3 is not accepted.

I have tried this

 <p:inputMask  id="time" value="#{cons.time}" styleClass="ore" mask="9,9" >
        <pe:keyFilter regEx="/([0-9]),(0|5)/g"/>
 </p:inputMask>

but the filter is not working.

Could you tell me what's wrong?

EDIT:

With wrong I mean that I could input for example a value like 6,2 . I saw someone suggesting using keyFilter with inputMask so that is why I used it. In response to #sheltem , I had already tried with inputText. It doesn't allow me to input anything at all. I cannot even paste a value like 6,5 , which should be valid. Maybe I don't understand how keyFilter works or maybe it only works for simple regex. Anyway, in the end I solved with Javascript.