The beauty of the Sampras Dampener is that it rarely comes out....IF your racquet spacing is right for the size. The Wilson Blx - no problem..has never come out.
Other racquets, it would fly out pretty often. So it matters the string pattern and the spacing.
Please help TT Member BruceD get a wheelchair so he can play tennis again - http://tt.tennis-warehouse.com/showthread.php?t=496820