This is Jack Up and Down Control Knob from Miller Industries. It is used on Control Assemblies of many Miller Wreckers that use a Jack control. These wreckers include Century, Challenger, Holmes and Vulcan Wreckers. Please see the features below for a list of wreckers and see the brochure tab for breakdowns.

• Jack Up/Down Control Knob
• Black w/ White Text
  
  Fits:
• Century 712 & 716 Wrecker Formula IIIT (04/1997 - Current)
• Century 820 Wrecker IIIT (02/1997 - Current)
• Century 1040B SDU (10/1994 - Current)
• Century 1040B SDU3 (06/2005 - Current)
• Century 1040S SDU (08/2000 - Current)
• Century 1060 SDU 2 (12/1998 - Current)
• Century 1060S SDU2 (01/2000 - Current)
• Century 1060S SDU3 (03/2006 - Current)
• Century 1075S SDU4 (11/2007 - 07/2011)
• Century 1075S SDU4 REV A (07/2011 - Current)
• Century 1140 & 1130 SDU4 & LDU, REV A (11/2009 - Current)
• Century 3212 (04/2004 - Current)
• Century 3224T (06/1996 - Current)
• Century 4024T T2 (01/1999 - Current)
• Century 5025T (04/2000 - Current)
• Century 5030 REV A (01/1999 - Current)
• Challenger 6807, 8807 & 9907 SDU2 (01/2002 - Current)
• Challenger 9909 & 8808 Rotators (12/2001 - Current)
• Challenger CH-16 (07/1996 - Current)
• Challenger CH-20T / T2 (07/1996 - Current)
• Challenger CH-30T / CH-30T3 (06/1996 - Current)
• Challenger CH-31 & CH-32 (06/2002 - Current)
• Challenger CH-35 (01/2001 - Current)
• Challenger CH-45 (05/2000 - Current)
• Holmes MD616T (11/1999 - Current)
• Vulcan V30 (05/2004 - Current)
• Product Dimensions: 1.5"L x 1.36"H x 1.36"H
• Inside Diameter: .3"
• Outside Diameter: 1.36"