A lithium-ion battery includes a positive electrode that includes a current collector that includes a positive electrode comprising a current collector and an active material comprising a material selected from the group consisting of LiCoO2, LiMn2O4, LiNixCoyNiO2, LiAlxCoyNiO2, LiTixCoyNiO2, and combinations thereof. for this purpose, the anaesthetic gas filter has an anaesthetic gas detector arranged in the filter. Yet another embodiment may comprise a frame having a base component, a vertical component, and a cross-member component, a rotation mechanism rotatably coupled with the cross-member component, and a protractor having a freely rotatable arm configured to couple with the golf club and measure an angle at which the golf club is rotated about the rotation point along a swing path. This operation lever portion can be operated while gripping a handle portion.