Complete replacement handslide assembly for King model 3B and 3BF small bore tenor trombones (models 2103 and 2103F). Standard 0.508 inch bore, with nickel silver outer slide tubes. Original OEM item made by King at the Eastlake, Ohio plant. Fits all King 3B and 2103 models current and older, dating back to the 1950's, except possibly very early prototype models and others that have been modified to accept different slides. Not intended for 3B+ or 2103PL models.