Chuck Arbor that is a Right Side Attachment ONLY (As you face it): 
A-JCA-2 (current lathes- built in 2002 and later with 5/16" motor shafts) 

Current models of BL Lathes refers to models built in 2002 and later. These lathes have 5/16" motor shafts. Older models (including Nos. 1 & 5 High Speed Bench Grinders)

Adjusts to hold accessories with shanks from 0-5/32".

Comes with chuck key.