Exhibit 10.4

Enclosure 1 to the guarantee dated Oct. 10, 2007 in the amount of EUR 9 Mio by
IPG Laser GmbH, Burbach

The following branches and subsidiaries of Deutsche Bank AG have entered into a
business relationship with subsidiaries of IPG Laser GmbH.

In this context subsidiaries of IPG Laser GmbH may draw funds up to a total
amount of EUR 9,000,000.00 within the EUR 20,000,000.00 umbrella credit facility
dated June 18th, 2012 based on the borrower’s guarantee in the amount of EUR
9,000,000.00 as listed below.

Summary of credit agreements for IPG Laser GmbH - group in Germany and abroad:

 

Debitor

  

DB branch /
subsidiary

   local curreny    amount (in k
currency)    cash/discount      guarantee      total             if not   
exchange value in k Euro  

IPG Laser GmbH, Burbach

   Siegen            10,000         3,000         13,000   

Credit lines under guarantee of IPG Laser GmbH

                 

IPG Photonics (Italy) S.r.l., Via Kennedy 21, 20023 Cerro Maggiore (Milano),
Italy

   Deutsche Bank Spa, Milano, Italy            4,000            4,000   

IRE-Polus NTO, 141190, Fryazino, pl. Vvedenskogo, Russia

   Deutsche Bank Ltd., Moscow, Russia            1,000         2,000        
3,000               

 

 

    

 

 

    

 

 

 

Total Credit lines based on the borrower’s guarantee

              15,000         5,000         20,000               

 

 

    

 

 

    

 

 

 

 

Burbach, 18 June 2012   Burbach, 18 June 2012   Seigen, 18 June 2012 place, date
  place, date IPG Laser GmbH   Deutsche Bank AG   Filiale Deutschlandgeschäft
/s/ Eugene Scherbakov   /s/ Joachim Gartz            /s/ Hans-Werner Bieler
legally binding signature(s)  

Being guarantor we agree with above mentioned changes of the facilites within
the Credit Facility Agreement dated June 18th, 2012 between IPG Laser GmbH and
the Bank regarding the Umbrella Facility in the amount of EUR 20 million.
Further we agree with all future changes within the Umbrella Facility and waive
seperate information thereof, provided that the allocation to subsidiaries of
IPG Laser GmbH does not acceed an aggregate amount of Euro 9 million
(cash/discount and for guarantees).

Oxford, Massachusetts, 26 June 2012

place, date

 

IPG Photonics Corporation /s/ Timoth P.V. Mammen legally binding signature(s)