The puttmaster stroke mat is held between two unbreakable pvc rails approx a large putter width 140mm apart strike the rails on your stroke and you will immediately see if you are out of alignment for advanced precision the mat can be removed trimmed narrower and reapplied to rails a white target line runs the length of the mat and has a number of precision ball placement spots indicated the mat can be either pegged or nailed down when on grass or velcrotaped for use on a carpeth