     *   optionally make it animated
     */
     private func showOff(animated: Bool) {
-        let normalKnobWidth = self.bounds.size.height - 2
+        let normalKnobWidth = knobSize.width
         let activeKnobWidth = normalKnobWidth + 5
         
         if animated {

        startTrackingValue = self.on
        didChangeWhileTracking = false
        
        let activeKnobWidth = self.bounds.size.height - 2 + 5
        isAnimating = true
        
        UIView.animateWithDuration(0.3, delay: 0.0, options: UIViewAnimationOptions.CurveEaseOut | UIViewAnimationOptions.BeginFromCurrentState, animations: {

    *   optionally make it animated
    */
    private func showOn(animated: Bool) {
        let normalKnobWidth = knobSize.width
        let activeKnobWidth = normalKnobWidth + 5
        if animated {
            isAnimating = true
