Gaps in fences regularly seen without reflection? (8)

'without reflection?' is the definition.
('reflection' can be 'echo' (echo is a kind of reflection) so maybe 'without reflection' can be ''echoless')

'gaps in fences regularly' is the wordplay.
'gaps' becomes 'holes' (hole is a kind of gap).
'in' is an insertion indicator.
'regularly' means one should take alternating letters (regularly take one letter, leave next etc.).
The alternating letters of 'fences' are 'ecs'.
'holes' placed into 'ecs' is 'ECHOLESS'.

'seen' is the link.