I found something. It is written that it is a tuning box increases the power of the engine. According to what is described quite a bit. I suspect that this is probably something like a resistor that changes the parameters of the intake air temperature. But maybe someone is interested 
1.0 Petrol 44kw 60HP 80 HP<br style="color: rgb255, 255, 255; font-family: 'Times New Roman'; font-size: medium; line-height: normal; : rgb7, 8, 7; ">1.0 Petrol 55kw 75HP 95 HP<br style="color: rgb255, 255, 255; font-family: 'Times New Roman'; font-size: medium; line-height: normal; : rgb7, 8, 7; ">1.2 Petrol 44kw 60HP 2007-> 85 HP<br style="color: rgb255, 255, 255; font-family: 'Times New Roman'; font-size: medium; line-height: normal; : rgb7, 8, 7; ">1.2 Petrol 47kw 64HP 2004-2007 89 HP<br style="color: rgb255, 255, 255; font-family: 'Times New Roman'; font-size: medium; line-height: normal; : rgb7, 8, 7; ">1.2 Petrol 51kw 70HP 90 HP
http://www.ebay.de/itm/VW-TUNING-BOX-POLO-6R-UP-FOX-1-0-1-2-PETROL-/110921636229?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item19d371d985#ht_3838wt_1528
1.0 Petrol 44kw 60HP 80 HP<br style="color: rgb255, 255, 255; font-family: 'Times New Roman'; font-size: medium; line-height: normal; : rgb7, 8, 7; ">1.0 Petrol 55kw 75HP 95 HP<br style="color: rgb255, 255, 255; font-family: 'Times New Roman'; font-size: medium; line-height: normal; : rgb7, 8, 7; ">1.2 Petrol 44kw 60HP 2007-> 85 HP<br style="color: rgb255, 255, 255; font-family: 'Times New Roman'; font-size: medium; line-height: normal; : rgb7, 8, 7; ">1.2 Petrol 47kw 64HP 2004-2007 89 HP<br style="color: rgb255, 255, 255; font-family: 'Times New Roman'; font-size: medium; line-height: normal; : rgb7, 8, 7; ">1.2 Petrol 51kw 70HP 90 HP
http://www.ebay.de/itm/VW-TUNING-BOX-POLO-6R-UP-FOX-1-0-1-2-PETROL-/110921636229?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item19d371d985#ht_3838wt_1528