This is a Replacement Motor Control Board Part Number 421600 for Various Proform and NordicTrack Treadmills Listed Below.

NordicTrack-
NTL10421.0
NTL10421.2
NTL10421.3
NTL10421.4
NTL10421.7
NTL10421C.0
NTL14124.1
NTL14124.4
NTL89121.0
NTL89121.2
NTL89121C.0
NTL89121C.2
NTL89122.2
NTL89122.3
NTL89122.4
NTL99020.1
NTL99520.0
NTL99520.1
NTL99520.2

Proform-
PFTL14821.0
PFTL14821.1
PFTL99720.0
PFTL99721.0
PFTL99920.0
23380