These

Four for the price of one anywhere else, even with £12 odd shipping they are less than half any other price for four, bargain or dodgy??

I doubt its dodgy in the sense of a scam, but they look poo. How can anyone say they'll give you +10 horsepower? More show than go.

If this means removing the trumpets from the carbs/tb's then you'll probably loose 10HP

I used one of those as a breather filter on an oil tank in my golf and it seems fine for that but as deezee says i doubt you'll get 10bhp extra from them, to be honest the design may even restrict airflow but for the price, looks and ease to fit they aren't too bad!

i got a set to fit 52mm diameter if you want some,my mate put some on his bike and i teamed up on his order for my gsxr t/b's.I have now fitted trumpets and dont need them,they have done 50 miles.Didnt notice any more power, they looked good and didnt take up much room.

If something doesnt look right then it probs isnt. Not worth it if they allow abrasive contaminants to pass through and damage something internally. Might be OK but do seem too cheap.

Don't really look any better or worse (functionally) than any other similar items I've seen.. Would be a bit doubtful for the price when proper K+N ones are in the region of £40-100

Remember - you get what you pay for...a tenner for 4 filters? And a 10bhp increase? Come on!!