From Amazon
Adapter: IC3 battery/IC5 device
eModels
Spektrum IC5 Device Connector to IC3 Battery Conn 4" / 100mm; 10 AWG # XCA507
Model Bau
Spektrum IC5 Female to IC3 Male 4" / 100mm; 10 AWG O-SPMXCA507 O-SPMXCA507
OnBuy
Spektrum Adapter: IC5 Device/ IC3 Battery, SPMXCA507