NiSi Macro Lens/Filter (Dual Element)

[bald-eagle]

Hi,
Does anyone have any experience of using this NiSi Macro lens/filter?
http://www.nisidigital.com/en/nisi/show/5a1f8994-f2d0-c62e-1e18-08cfcdae9cbc
Cheers,
Baldy