Title: Steady Swing™ Golf Aid: Guaranteed to Reduce Head Movement

Description: Steady Swing™ will transform your personal eyewear into a visual training aid. Your transformed eyewear will produce the appearance of a red tinted rectangular “training window” over your ball at address. During use simply attempt to minimize the training window movement as you perform your putting stroke or full golf swing. Even the slightest head movement during your putting stroke is detected by seeing the window move!

Link: http://www.steadyswing.com/