Simphony MasterData web service

I am trying to use master data web service to create new items, but there is no available documentation with some examples.

My request is as follows:

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:inv="http://webservices.micros.com/inventory_management/" xmlns:dat="http://webservices.micros.com/inventory_management/DataStructures">

   <soapenv:Header>

      <inv:MDWebServiceHeader>

         <inv:User>*****</inv:User>

         <inv:Password>*****</inv:Password>

      </inv:MDWebServiceHeader>

   </soapenv:Header>

   <soapenv:Body>

      <inv:ImportMasterData>

         <dat:MasterData>

            <dat:Items>

               <dat:Item>

                  <dat:Number>9999</dat:Number>

                  <dat:Name>TEST 11</dat:Name>

                  <dat:UnitNumber>62</dat:UnitNumber>

                  <dat:ItemGroupNumber>73</dat:ItemGroupNumber>

                  <dat:CountInterval>OnDemand</dat:CountInterval>