| 
       in CHF 1 000  | 
    
       Notes  | 
    
       2024  | 
    
       in %  | 
    
       2023 restated 1)  | 
    
       in %  | 
  
| 
       Net Sales  | 
    
       480 836  | 
    
       100.0  | 
    
       389 890  | 
    
       100.0  | 
  |
| 
       Change in inventory of finished and unfinished goods  | 
    
       
  | 
    
       –4 810  | 
    
       –1.0  | 
    
       1 060  | 
    
       0.3  | 
  
| 
       Material costs  | 
    
       
  | 
    
       –237 099  | 
    
       –49.3  | 
    
       –208 210  | 
    
       –53.4  | 
  
| 
       Personnel costs  | 
    
       –135 811  | 
    
       –28.2  | 
    
       –102 468  | 
    
       –26.3  | 
  |
| 
       Other operating income  | 
    
       
  | 
    
       758  | 
    
       0.2  | 
    
       1 455  | 
    
       0.4  | 
  
| 
       Other operating expenses  | 
    
       –45 521  | 
    
       –9.5  | 
    
       –36 592  | 
    
       –9.4  | 
  |
| 
       EBITDA  | 
    
       
  | 
    
       58 353  | 
    
       12.1  | 
    
       45 135  | 
    
       11.6  | 
  
| 
       Depreciation and impairment  | 
    
       –12 962  | 
    
       –2.7  | 
    
       –11 686  | 
    
       –3.0  | 
  |
| 
       Amortization and impairment  | 
    
       –7 305  | 
    
       –1.5  | 
    
       –4 404  | 
    
       –1.1  | 
  |
| 
       Operating profit (EBIT)  | 
    
       
  | 
    
       38 086  | 
    
       7.9  | 
    
       29 045  | 
    
       7.4  | 
  
| 
       Financial income  | 
    
       13 016  | 
    
       2.7  | 
    
       7 063  | 
    
       1.8  | 
  |
| 
       Financial expenses  | 
    
       –15 597  | 
    
       –3.2  | 
    
       –15 425  | 
    
       –4.0  | 
  |
| 
       Profit before tax (EBT)  | 
    
       
  | 
    
       35 505  | 
    
       7.4  | 
    
       20 683  | 
    
       5.3  | 
  
| 
       Income tax  | 
    
       –8 252  | 
    
       –1.7  | 
    
       –8 923  | 
    
       –2.3  | 
  |
| 
       Net profit  | 
    
       
  | 
    
       27 253  | 
    
       5.7  | 
    
       11 760  | 
    
       3.0  | 
  
| 
       
  | 
    
       
  | 
    
       
  | 
    
       
  | 
    
       
  | 
    
       
  | 
  
| 
       Earnings per share (in CHF)  | 
    
       
  | 
    
       
  | 
    
       
  | 
    
       
  | 
    
       
  | 
  
| 
       - basic  | 
    
       6.20  | 
    
       
  | 
    
       2.66  | 
    
       
  | 
  |
| 
       - diluted  | 
    
       6.05  | 
    
       
  | 
    
       2.63  | 
    
       
  | 
  
1) Refer to note "2.2.1 Change to the Consolidation and Valuation Principles - Accounting for Goodwill".