A lamp , comprising: a casing , having an opening and an outer surface ; an elastic cover , covering the outer surface of the casing ; characterized, in that the lamp further comprises a main body , disposed at the casing , the main body comprising: a base plate ; a rotating element , pivoted to the base plate and located at the opening ; a fastening element , disposed at the base plate ; a moving element , having an engaging portion , the moving element being disposed at the base plate and moved between a first position (P1) and a second position (P2); a linking-up element , having a first end and a second end , the first end being connected to the rotating element , and the second end being connected to the moving element ; and a force member , connected to the moving element , when the force member receives a force, the moving element is moved from the first position (P1) to the second position (P2), the engaging portion is engaged with the fastening element , the second end of the linking-up element is moved to the second position (P2) with the moving element , the first end of the linking-up element brings the rotating element to rotate away from the base plate , and the rotating element is protruded from the opening and pushes against the elastic cover . a casing , having an opening and an outer surface ; an elastic cover , covering the outer surface of the casing ; characterized, in that the lamp further comprises a main body , disposed at the casing , the main body comprising: a base plate ; a rotating element , pivoted to the base plate and located at the opening ; a fastening element , disposed at the base plate ; a moving element , having an engaging portion , the moving element being disposed at the base plate and moved between a first position (P1) and a second position (P2); a linking-up element , having a first end and a second end , the first end being connected to the rotating element , and the second end being connected to the moving element ; and a force member , connected to the moving element , when the force member receives a force, the moving element is moved from the first position (P1) to the second position (P2), the engaging portion is engaged with the fastening element , the second end of the linking-up element is moved to the second position (P2) with the moving element , the first end of the linking-up element brings the rotating element to rotate away from the base plate , and the rotating element is protruded from the opening and pushes against the elastic cover . a base plate ; a rotating element , pivoted to the base plate and located at the opening ; a fastening element , disposed at the base plate ; a moving element , having an engaging portion , the moving element being disposed at the base plate and moved between a first position (P1) and a second position (P2); a linking-up element , having a first end and a second end , the first end being connected to the rotating element , and the second end being connected to the moving element ; and a force member , connected to the moving element , when the force member receives a force, the moving element is moved from the first position (P1) to the second position (P2), the engaging portion is engaged with the fastening element , the second end of the linking-up element is moved to the second position (P2) with the moving element , the first end of the linking-up element brings the rotating element to rotate away from the base plate , and the rotating element is protruded from the opening and pushes against the elastic cover . <EOS>