Fender extender.

[Andy FZS]

Hi, I'm thinking of getting a fender extender to stop all the water (If I miss judge the weather) stones and debris etc from being thown at my engine rad etc. My question is who has on,e do they work, are some better than others, should any be avoided. I just thought I'd ask before I buy one, I've seen them for under £20 but if a couple of quid more is money well spent then so be it. But I'm a Yorkshireman and don't want to waste money.
Thanks
Andy