No. 1 Morse Taper Arbor with Jacobs brand 3-jaw screw on type drill chuck.
Arbor and chuck have 1/2"-20 threads. Chuck capacity is 1/2" (1.5 - 13mm).
Fits an MT1 Headstock Spindle or Tailstock Ram.
Will fit all brands and models of wood and metal lathes with Morse Taper No. 1 MT1 spindles. Most Craftsman 103.xxxxx and 113.xxxxx series 9" and 12" wood lathes have MT1 spindles