I bought these to rebuild my swingset that was made out of 4x4s and a 4x6.  This was simple to install and setup.  There are no instructions with these items but they are pretty self explanitory.  I did put a cross bar between the legs and anchor all 4 legs.  Today, my wife and daughter were both swinging at the same time (16ft 4x6) and it didn't concern me at all.