This tool provides immediate feedback on whether a revolver's barrel and cylinder are perfectly aligned and if the cylinder crane or yoke has been bent, which can misalign the axis of each with the barrel bore. It is essential for timing and accuracy assessments, identifying the cause of lead splatter and conducting professional service inspections. It is also an excellent tool for demonstrating to customers the reasons behind any issues. The handle, featuring a knurled grip, is threaded to accommodate interchangeable heads, with sizes precisely chosen to detect even minor misalignments. The .38 Cal heads come in two diameters - one for match guns, which require precise alignment for optimal performance and one for service guns, which may not always be thoroughly clean and do not need to meet as stringent accuracy standards. Additionally, there is a special head designed for the S&W K-22, which has a slightly undersized bore.