The Audio2000'S ACC4392-01 is a 1-3/8 inch external speaker stand mounting top hat for fitting on a 1-3/8 inch standard speaker stand shaft. The ACC4392-01 is typically to be mounted on the bottom of a loud speaker for the loud speaker to be mounted onto a speaker stand. Constructed with high quality plastic material, the ACC4392-01 is rugged and durable. The mounting hardware is included in the package. This ACC4392-01 is designed for AST420y-15, AST4392B, AST4395B, AST4397A, AST440B, and other standard 1-3/8" speaker stand.