RENNtech ECU Hand Held Tuner (HHT) for SL 65 | R230 | 670 HP / 840 LB-FT | MY2005-2006RENNtech ECU HHT (HandHeldTuner) for the 230 SL 65 AMG. Up to 670HP and 840 LB FT LB FT. Gains: +66HP & +102LB FT. RENNtech HHT (hand held tuner) allows you the unlimited ability to switch between tuned and stock ECU programming and requires no ECU removal! Our proprietary tuning module stores both the RENNtech tuned file and your vehicles stock file. The module plugs directly into the OBD2 port and delivers the file you choose directly to the ECU.