The Audio2000'S ACC4392-12 inclule one pair (two sets) of ACC4392-01 which is a 1-3/8 inch external speaker stand mounting top hat for fitting on a 1-3/8 inch standard speaker stand shaft. Each of the ACC4392-12 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 ACC4392-12 are rugged and durable. One mounting hardware set is included in each package (total two harware sets). These ACC4392-12 are designed for AST420Y-15, S4397P2, AST4398, AST4399, AST439A, AST439C2 and other standard 1-3/8" speaker stands.