Ⅰ: Product series: three-digit

     156: series 156 micro switch

Ⅱ: Button type: single-digit

     1: column      2: sector   3: square

Ⅲ: Free position: double-digit

     85: FP=8.5mm    37: FP=3.7mm 

     35: FP=3.55mm  52: FP=5.2mm

Ⅳ: Fixed method: single-digit

     0: SMT, type "一" terminal

     1: SMT, type "Z" terminal

     2: SMT, type "V" terminal

     3: DIP, type "S" terminal

     4: DIP, type "八" terminal

Ⅴ: Operating force(OF): double-digit

      08: OF=8gf  35: OF=35gf  70: OF=70gf

Ⅵ: Product life: single-digit

     0: 5000 times 1: 5M times  2: 10M times  3: 20M times

Ⅶ: Derivative code: double-digit

     00: without special items

Ⅷ: Package type: single-digit

     0=plastic bag         1=shrinked plastic package

     2=tape package          3=tube package

     4=foam  package        5=undetermined