The M++ tip is a medium-wide tip. The M+ is the shape that Mr. Mack endorses and uses himself, and is also the design most oboists prefer. There is also the M, which is slightly narrower, and the M++, which is a slightly wider shape. For each RDG/Mack Shaper Tip purchased at RDG, a $30.00 donation is made to the Cleveland Institute of Music Scholarship Fund. All returned shaper tips are subject to a 15% restocking fee.