ND Filter looks good for the money

[shannensdaddy]

Has anybody seen or used anything like this http://www.amazon.co.uk/Adapter-Filter-G-ND2-Holder-Canon/dp/B009GTM6H6/ref=sr_1_5?ie=UTF8&qid=1403317980&sr=8-5&keywords=ND filter 77mm
They seem good for the money involved .