- Only for models without immobilizer - Aprilia RS 50 Bj. 2006-2010 (Derbi D50B0 engine) Aprilia RX 50/MX 50 Bj. 2006-2010 (Derbi D50B0 engine) Aprilia RS 125 Tuono Bj. 2003-2004 Aprilia RS 50 Tuono Bj. 2003-2004 Aprilia RS4 50 2T year. 2011-2015 Aprilia RS4 125 4T year. 2011-2013 Aprilia RS4 125 4T year. 2014-2015 If you have any questions, write us a message or call us. Please do not immediately give a negative review just because something is not as we described it or because something strikes you as wrong. Please remember that we are only human and make mistakes every now and then. In such a case, you do not need to be afraid to contact us. We want to offer you super service. And if we make a mistake, we'll fix it again. We will generally treat you in a nice and friendly manner. We pro