When supplied lamp lacked the battery contacts. Even otherwise it is composed rather primitive. To open the battery compartment, the lamp ring is only unscrew, but please very carefully so as not to bend the many small LEDs. The printed on the packaging manual is completely incomprehensible. And much too small. (Can be natural that my arms are too short.)
Amazon has "a good piece" withdrawn when they should change (it can not well be any light is not working). For that I probably had not settled the right return receipts. But okay, everything regulated.
