As always, very fast delivery. Very securely packaged, only now you need heavy equipment aufzubekommen around the blister. The device itself properly and working. About measurement errors I can not say anything because I use it for volume calculations which are not relevant to one decimal place. Should I use it constantly, a more universal device and a previous test I would certainly have been welcome. It goes well and does what I want. Addendum: in bright sunny days the laser is not very easy to determine, respectively. until I sometimes find the point it turns off ... should go wenns quickly it is corrosive.