That is correct but the one fitted to the '335S (Target) was unique in that it didn't have the ability to adjust to different dove tail widths as most Williams/Beeman sports peep sights but a single grub screw at the front which went vertically down.
These are the normal ones and as you may be able to see they are adjustable for various width rails. The one on the 335S isn't.
The 335S one.