A quick learner from Castleton on Hudson, NY says:
June 30, 2019
The Base dimensions are 1 1/4" wide by 2" high. The socket slide is 4 1/4" long and accepts a 7/8" rail. I need both Left and Right sockets.
Tom from SWISCO responded:
July 8, 2019
Thanks for posting! If the opening that accepts the rail is 7/8", then consider our 32-018 as a replacement. Look over our dimensions and let me know what you think.