How to allow upto 3 decimal places only in textfield in ExtJS

For a textfield I need to allow it upto 3 decimal places only.

Allowed inputs : 123, 123.1, 123.34, 123.458 but 123.4563 should not be allowed.

I tried so many articles but found upto 2 decimal places only.

I don't know why are you using textfield for number field. Anyway, here is fiddle code for text field and number field with decimal precision 3.

Ext.application({
    name: 'Fiddle',

    launch: function () {
        Ext.create('Ext.form.Panel', {
            title: "Form Panel",
            width: 300,
            renderTo: Ext.getBody(),
            layout: 'form',
            items: [{
                xtype: 'numberfield',
                name: 'bottles',
                fieldLabel: 'Number Field',
                decimalPrecision: 3 // This will allow only 3 decimal places.. 
            }, {
                xtype: 'textfield',
                name: 'name',
                fieldLabel: 'Text Field',
                maskRe: /[0-9.-]/,
                //regex: /^-?[0-9]*(\.[0-9]{1,3})?$/, // Without error message
                validator: function (v) { // With error Message
                    return /^-?[0-9]*(\.[0-9]{1,3})?$/.test(v) ? true : 'Max. decimal precision is 3';
                },
            }],
            buttons: [{
                text: "Show Form Values",
                handler: function() {
                    console.log(this.up('form').getValues());
                }
            }]
        });
    }
});