1" Straight Shank Flush Milling Arbor. Fits cutter I.D. 1" or 1-1/4". Widths from 1/8" to 3/4".
Shank is 1" dia. Diameter behind cutter is 1.765".
Parts included: Arbor body, Bushing for 1" I.D. Cutter, 3 spacers for 1" I.D. cutter, Key for 1" bushing.
Bushing for 1-1/4" I.D. Cutter, 3 spacers for 1-1/4" I.D. Cutter, key for 1-1/4" bushing. 
Pusher(Washer) , Screw, Allen Wrench.