Mushroom blade is easy to use and cuts well through sealant when removing double glazing from window frames. The pickup range is suitable for all brands of multi-vibration tools. Fein makes less expensive mushroom inserts, but they only have a star tip. I was surprised that the blade section would loosen and detach from the attachment section. It is good that there are five blades in the kit, because for a large job you need to use several. I've also found that if you put too much pressure on the sealant, the 12 volt battery and multi-tool get hot and stop working. Nevertheless, the blade does its job.