That group of timers are for the normal Ford magneto and coils, but have different design to improve on life.
The New Day is a brush style, with a forward facing brush making contact with terminals in the face of the housing.
T timers are normally Ford style roller contact, with roller making contact with terminals in the inside edge of the timer.
Then, there is the flapper type, Anderson, which has a hinged flapper that makes contact with steel terminals around the inside edge of the housing.
Photo one shows (l to r) the Ford, the New Day and the Anderson
.
TW timer is the newest one, which is brush type, using a carbon brush making contact with terminals on the inside edge of the housing. The TW is complete with new housing, but similar to old timer called the M-F.
Lastly, the E-Timer is completely different, using a Hall Sensor, and NO Contact to the housing, no wear. It is all electronic and is high tech, doing many functions, operates only on battery, with Ford trembler coils shunted.