This is a replica of the cartridge alignment tool that was provided with Harman Kardon linear tracking turntables. This tool is intended for use with the Rabco arm wands on ST-5, ST-6, ST-7 and ST-8 models. Please exercise care when using this item so as not to damage your stylus assembly. Please note the following: 1/ This model is based on information posted on AK forums rather than measurements made by myself using an original alignment tool. 2/ There may be some minor dimensional variations caused by the printing process which is outside of my control. As a result, this tool should not be considered to be an exact copy of the original. If you find this product useful, please consider becoming a subscriber to the Audiokarma forum which makes all of this possible.