KYOSHO EasyLap Digital Timing System (No Transponders) EZL01 (EZL01) This Lap Timing System is a fully operational lap counting system for all RC Model of all sizes. The transponder is extremelysmalland will fit any RC cars. (No Transponders included) Every transponder is encoded withauniqueID. Feature: l. For Indoor and Outdoor Tracks 2.Unlimited cars 3.Personal transponder with unique ID (Compatible with Robitronic) 4.Small(only 12x12x6mm)and lightweight Transponder(1.2g) 5.Software for all Windows System(RCM or Zround) 6.Fully USB Support 7.Receiver Modules with Power Led & Action Led Display System Requirement: 1.Windows 2000 , XP, Vista, Windows 7,Windows 8 or 8.1 (32/64-Bit System Support) 2.One available USB 2.0 port 3.Installing Drivers 4. Build your own bridge by any material like PVC pipe or wood. Height recommendation from sensor to ground (16 inches/40.6cm) Lap Timing System in Box 1 x USB PC-Interface with data cable 1 x 4 Receiver Modules for track with max width (4 feet/1.2 meter)