This is a very well built professional accordion. Now SEM is part of the Suoni company along with Menghini, Scandalli, and Paolo Soprani. The trend is to keep the name for reedless accordions. It seems like this is one of the last top of the line acoustic model with 4/5 sets of hand made reeds, double tone chamber, genuine leather reeds valves, and excellent mechanics throughout. 

• Made in Italy, Model 502-D Argento
• Excellent Hand Made Reeds with leather valves
• 4 sets of treble reeds - LMMH - Continental Musette Tuning
• 5 sets of bass reeds
• DOUBLE TONE CHAMBER (CASSOTTO) - Bassoon and Clarinet
  
• 5 sets of bass reeds
  
• 41 keys, 19.25 " keyboard - wooden keys with pearl key tops - smooth edges - a delight to play
  
• 11 different treble switches
  
• Palm Master switch
  
• 120 bass with 7 bass registers
• Low-G bass reed configuration
  
• 17-fold bellows with excellent compression
  
• Backpad for bellows protection
• Excellent straps
  
• Hard-shell case with internal padding
• 27 lb 

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