I am currently working with stand alone solar photovoltaic systems and when installing these systems the metal boxes of the housing house the inverters, converters, chargers. Controller and battery boxes, needs revision. For example, cable management can be made easier with the right hole size in the metal housing. Then this metal cutting kit will save you day, time and even money. A round carbide saw shank and additional bits are designed to cut precise round holes, while an over-drill stop prevents over-drilling and a spring mechanism in the center of the blade pushes the dowel out after the hole has been cut. A safety owner's manual and a table of specific RPMs for each size of carbide seeding shop and accessory bits are included, but there is no owner's manual as such. So I basically used my drilling and chiseling experience to try different parts. I absolutely love this set and have already checked out some other great tool accessories on the Lenox website that I would love to have in my tool arsenal. It's worth noting that the kit includes a hard case to keep all the parts together and last longer.