This is the HTS-ORPM Optic RPM Sensor from Hitec. FEATURES: Provides optical RPM information For use with Hitec Telemetric AFHSS System INCLUDES: One Optical RPM Sensor Double Sided Foam Tape Two 1.5x9mm Screws Two Zip-Ties REQUIRES: Hitec Telemetric AFHSS System SPECS: Length: 1.42" (36mm) Width: 1.02" (26mm) Height: 0.47" (12mm) Wire Length: 9" (228.6mm) COMMENTS: For additional information contact Hitec lmm 10.5.10 ir/jxs