OK, my new SAK classic with integrated Whistle arrived a few days ago. However I thought I would wait until I had some experience with it before posting.

Overall, as Doug says, it is a pretty good bit of kit. It weighs next to nothing and happily sits next to a regular door key lengthwise. The one red scale is oversized to accomodate the whistle, which is reasonable loud. Not Fox 40 level, but it is not even as large as the flat Micro version of the Fox 40 so it is pretty impressive. Overall I would recommend it, especially for people who cannot easily carry/conceal anything larger such as people that have to wear a business suit and also a first knife for kids, where the whistle is a great little addition.

It seems the Classic with Whistle is a North American model of SAK. I got mine from 7dayshop.com who I would recommend to any UK based readers as they are local and avoid the VAT by being based in the Channel Islands.