I opened the upper part of the machine before I used it myself and there is grit inside. The machine is used!

correct, we do a very small test before packing everything.

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It is a brandnew tool and we are still learning/optimizing and to avoid you receiving a BLSTRsander that does not work propperly, we test with a small amount of grit to be sure. It makes our production process longer and more expensive, but we want to deliver a good machine that you can enjoy for a long time.

However, inhouse Quality Control is still not the same as real usage by you. So, yes there can still be issues. Forgive us, we do everyting to improve. On a daily basis. If it is the case please contact us, and we will find a good solution for you.