A butterfly opening razor is also called a twist-to-open razor. It has a special twist function at the end of the handle that uses a special fine mechanics to make it easy to change the razor blade.
With a butterfly razor, you don't have to twist off the razor head itself every time you change the razor blade, so there are no loose parts to keep track of.
To insert your razor blade, simply twist the bottom of the handle. This action causes the top part of the razor to open (and looks a bit like a butterfly - hence the name). Then simply insert your razor blade and twist the opposite way than before to secure the razor blade.
We have both double edge razors and single edge razors with butterfly opening in our range - and we've collected them all below.