These servo frames work with the popular Emax ES08xx servos which includes: ES08A, ES08MA, ES08MD, & E08DE.
Each set comes with Left & Right - A/B versions and servos are "locked in" with two guided pins using the mounting screws that are included with each servo. These are extremely robust frames for horizontal mounting and weigh less than 1.2g each.
I've used these for both Ailerons, Flaps and Rudders with good results in Sailplanes/Gliders, 3D Planes, and EDFs.
These were originally created because I found the "Shrink Wrap Method" to be lacking when it comes to removal and upgrading.