Low hour, 1997 H&T 635 mounted on tracks is great for high production small diameter drilling. drilling up to 35 feet deep with single 3 1/2″ kelly bar and will out perform any Texoma 600 on the jobsite. A short-mast and kelly bar set which includes an extra rotary, is also available for additional cost while it lasts. This unit is the sister rig of the 1997 H&T 635 on the 1999 GMC truck also listed for sale on this site.