Staples for Rapid S51, F51 pliers
also fit Zenith 548E, Zenith 530 staplers
Made in Sweden

 CODE     | LENGTH |  M/   | 1-19  | 20 + | WT/ | Click  
          |        |  PKG  |       |      | PKG |        
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21/4        5/32"    5M      4.15    3.45   0.1   
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Rapid SS Interchange Staples
Made in Germany

 CODE     | LENGTH |  M/   | 1-5   | 6  + | WT/ | Click  
          |        |  PKG  |       |      | PKG |        
___________________________________________________________
21/4 Monel  5/32"    5M     20.85   18.55   0.2   
21/4 SS     5/32"    5M     20.85   18.55   0.2   
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SS: rust resistant, made with low iron content wire
Monel: rust proof, made with no iron content wire. Highly resistant to corrosion.
Because of the nickel content, it would have a life more than double to triple that of a 316 stainless material. more info