That! Inventions "SpreadTHAT!" Self-Heated Butter Knife, Silver/Red, 17.5 x 1.5 x 0.3 cm

The combination of its shape design, blade profile and material makes it an efficient tool for spreading cold butter, but also works with cold Nutella and chocolate spreads. Fits very well in the hands. The decoration on the handle is a bit misleading, as it looks like a button to press in order to get it work, but I have no issue with that. It is also good to have colour variations I can choose from.

Good to be able to spread cold butter in the depth of winter. Takes slightly longer that soft butter but that is only to be expected.

It simply doesn't work even if I hold it in my hand for several minutes before using.

Incredible. It really works!!! No matter how solid the butter, this knife can slice through it with incredible ease. I love it and want to get the ice cream scoop as well - even though I don't eat it!

This works quite well for me because my hands are almost always warm, but I bought it as a Christmas gift fir my daughter and it doesn’t work for her at all. Having shaken hands with others, mostly cold hands, over the years, I would say that this is unlikely to work for most people. I hope I’m wrong. Maybe it could be warmed on a radiator before use instead? Not sure. I did find that the knife itself was making my hands cold after a short time though, so needed to change hands to keep it slightly warm.

Was not convinced this would work and it absolutely worked ! very simple very clever!

Very expensive mistake on my part. The only time my hands get warm is in the summer, when the butter is soft anyway! However, it suffices as a spreading knife because of the serrations on the edge. The blade takes forever to warm up in my hands, and I have other things to do apart from clutching knives! So, I do regret spending a lot of money on an ordinary butter knife!

this model is a little heavier than the original but the serrated edge is much better and more efficient with cold butter. Very good