I had to replace my Wiss thread cutter. The blades no longer cut. But since I bought it in 1967 (50 years ago) I got my money's worth. This type of clipper has many advantages: sharp blades (that's a problem with my old clipper), blades always open and ready to cut thread, comfortable grip, and a plastic sheath to cover the blades. Some of the complaints concerned people being stabbed. In the 50 years that I've used clippers, I've never cut myself, and I didn't have a protective case for them…