1.When the telescopic extended, it is smooth, no bending, shape changing, no dust on the surface . 2.Size:contracting length is 220mm±5mm, extending length is 512±5mm. 3.Weight:550g(stainless steel material), 290g(aluminum alloy) 4.Material:stainless steel tube hardness hv480-hv550, project plastic, kirsite, epdm 5.Anti corrosion:after 24 hours salt test, the baton with anti corrosion 9 level 6.Work life:incredibly strong and durable, expand and collapse more than 3000 times, beat more than 1000 times