The base unit and the additional inner marker have red rails that help you Line Up your Putt so you have the confidence in seeing the line and can then go ahead and knock it in.
Exceptional Poker Chip Size Marker that provides two additional functions in one item. Please review all the pictures included. The base unit measures 1 3/8" across x 1/4" thick and has a strong magnet in it that holds another 1" marker on the inside ring. The inner marker can be removed when closer to the hole or in a competitors way. Both the base unit and the inner marker have red rails that help you Line Up your Putt so you have the confidence in seeing the line and can then go ahead and knock it in. However you can still use the small marker to line up your putts.
The marker quality is fantastic and is slightly larger than a 50 cent piece. The phrase "Line it up and Knock it in" is a good reminder to putt with confidence.