This works well with the Blaster, the muscle has to work much more intensively than with free-hanging arms. Bad for the ego, because by lack of support from swing / shoulder a dumbbell than the otherwise usual variant must be selected by the Blaster-use quite.
One thing I have to complain about: the padding, which sits at the neck is too thin and the surface of her simply too small to slip it on easily. It is certainly the more "hardcore", but would definitely be enjoyable a bigger / thicker neck pad
Conclusion: This simple but effective tool for arm training should be in every (home) Gym!