These perches are made from natural growing Manzanita wood, and shapes will vary from perch to perch. Each perch is made based on the width of the branch and cut to an average length, giving them a distinct small, medium, large, and extra large size. 
 
 
 
These perchest are on average 18" long.
 
 
 
Natural Manzanita perches still have the bark on. This gives your bird bark that it can strip off, but the wood underneath is incredibly strong and should stick around for quite some time. However the bark left on does make the perch a bit harder to grab and might not be the best for very young or very old birds.