The combination of the mirror and string provides instant feedback for perfect eye alignment. Guide lines help you develop an on-line stroke to the reduced size cup. Built in gravity control ball return. The Targaline can be used indoors or outdoors and is equally effective without the carpet & ramp. The key is the mirrored base with level which reflects an image of the target line. If the player is correctly positioned they will only see 1 line. If the eyes are inside or outside the line they will see the real string & the reflection in the mirror. For more information visit: www.targaline.com Availability: Usually ships the next business day. Targaline Putting System TARGARegular price: $69.95GTA cost: (c) GolfTrainingAids.Com - since 1985