Developed by piano technician, Glen Hart, this patented spring tool is considered the best one in the industry. Measuring 7" long with a plastic sleeve handle, the tool is made of stainless steel and will last a lifetime. Referring to the diagram, notice the circular notch (1) that allows tool use in any position. All types of upright and grand piano action springs can be manipulated from any angle without any worry about kinking. Another unique advantage of this spring tool is shown as item (2) in the diagram. The distance from the flat side of tool to the notch equals the measurement from the side of the repetition lever to the center of the spring seat. Grand repetition springs can be removed and replaced without any guesswork.