687-02538 (MTD Adapter W/ Pulley)
 
2.85 in Height
25 mm Inside Dia.
2.8 in Pulley Dia.
Bow Tie Center Pattern
 
Some models that use this adapter: 
 
Yard Man
12A-B29Q701 (2011) Self Propelled Lawn Mower
12AEB2JA001 (2011) Self Propelled Lawn Mower
12A-B29Q701 (2013) Lawn Mower
12A-B29Q701 (2012) Lawn Mower
12A-B2AQ701 (2014) Lawn Mower
Troy-Bilt
12A-A26M011 (2010) Push Walk-Behind Mower
TB210 (12A-A26M011) (2010) Self-Propelled Walk-Behind Mower
12A-A26M066 (2010) Self-Propelled Walk-Behind Mower
TB210 (12A-A26M066) (2010) Self-Propelled Walk-Behind Mower
12A-A26N211 (2010) Self-Propelled Walk-Behind Mower
TB210 (12A-A26N211) (2010) Self-Propelled Walk-Behind Mower
12AEA29L011 (2010) Self-Propelled Walk-Behind Mower
TB270ES (12AEA29L011) (2010) Self-Propelled Walk-Behind Mower
12AEA29L066 (2010) Self-Propelled Walk-Behind Mower
TB270ES (12AEA29L066) (2010) Self-Propelled Walk-Behind Mower
12AEA29M211 (2010) Self-Propelled Walk-Behind Mower
TB270ES (12AEA29M211) (2010) Self-Propelled Walk-Behind Mower
TB210 (12A-A26M011) (2011) Self-Propelled Walk-Behind Mower
TB210 (12A-A26M066) (2011) Self-Propelled Walk-Behind Mower
TB210 (12A-A26N211) (2011) Self-Propelled Walk-Behind Mower
TB210 (12A-A25S011) (2012) Self-Propelled Walk-Behind Mower
TB210 (12A-A25S066) (2012) Self-Propelled Walk-Behind Mower
TB210 (12A-A25U211) (2012) Self-Propelled Walk-Behind Mower
12A-B22Q563 Self Propelled Mower
12A-A25U711 (2012) Lawn Mower
12A-A25U711 (2013) Lawn Mower
Murray
12AA04Z758 (2013) Self-Propelled Walk-Behind Mower