There is a button that switch on, off and change the lamp brightness. Simply hold his finger on the button to change the brightness.
Its weight without batteries is 96 grams and adds them if this is 132g. One can vary the brightness of 120 lumens (life of about 10h battery) which illuminates approximately 8 meters Around 4 lumens (battery lasts approximately 160 hours) which illuminates to 2 meters around itself.
It has 2 rings to hang it be when we went camping. Since she is IPX4, it is protected against water sprayed from all directions (watch that does not mean waterproof). So in case of rain, it will not be a problem.
Personally, I took it mainly for our meals on the terrace in summer to enlighten us in the evening (we have no light outside) and campsites We will.
I found it really well lit without hurting the eyes.