looks like the difference between the sensored 1415 - 1y - 2400 kv castle motors and the non sensored motors are indicated by the wire colours and the exposed soldering of the 3 motor wires. the new sensored 1415 motor has 3 x black motor wires plus exposed solder joins to these wires plus a socket on motor end for sensor wire to esc. the older non sensored 1415 has 3 x coloured wires [ red / white / black ] plus there is a neat rubber type cover where the wires enter the motor also no plug socket for sensor plug. it would be nice to know the full specs on both motors to see which of the 2 designs has the most power etc, castle don,t seem to give much info away on there products.