Options front assembly: USB – interface, with plastic trackball Order number SURTA4F/TB1/USB/D USB – interface, with stainless steel trackball Order number SURTA4F/TB2/USB/D Process data highway-interface, with plastic trackball Order number SURTA4F/TB1/PRB/D Process data highway-interface, with stainless steel trackball Order number SURTA4F/TB2/PRB/D Country-specific variants upon request |