You won't have to look all over the shop for which key fits which chuck because each of these 4-way chucks fits literally hundreds of drills. Between the two you can open almost any 1/4" to 3/4" drill chuck:

825-823 - Masterchuck I fits 1/2", 3/4" and heavy-duty 3/8" chucks.

825-830 - Masterchuck II fits 1/4", 3/8" and light-duty 1/2" chucks.

Durable black oxide finish protects the treated steel. The square hole in the center opens and closes acetylene tanks.

Buy both (826-433) and save!

USA.