This is the Micro 4-Channel Receiver for the Traxxas E-Maxx. FEATURES: 27MHz AM operation Replaces damaged receiver INCLUDES: Installing in vehicle and connecting servos and battery SPECS: Length: 1.5" (38.5mm) Width: 0.98" (25mm) Height: 0.83" (21.3mm) REQUIRES: Crystal to match transmitter frequency, TRAL2031 2031 #1 CRYSTAL SET BRN 26.995 TRAL2032 2032 #2 CRYSTAL SET RED 27.045 TRAL2033 2033 #3 CRYSTAL SET ORG 27.095 TRAL2034 2034 #4 CRYSTAL SET YEL 27.145 TRAL2035 2035 #5 CRYSTAL SET GRN 27.195 TRAL2036 2036 #6 CRYSTAL SET BLU 27.255 Crystals sold as a set only-not available separately jxs 1/23/08 ir/jxs