An electric device includes a main body, a supporting crutch and a pivot mechanism connecting the body to the crutch. The body is rotated around the crutch through the pivot mechanism. The pivot mechanism includes first and second bearing shims. The first bearing shim has a limiting salient, which has a first sidewall, a second sidewall and an inclined surface. The inclined surface is tilted from the second sidewall to the first sidewall. The second bearing shim has a sliding salient. When the sliding salient is disposed on the first/second sidewall, the main body is positioned at a first/second position. The sliding salient crosses the first sidewall and slides on the inclined surface to the second sidewall by a first force. The sliding salient crosses the second sidewall and slides on the inclined surface to the first sidewall by a second force larger than the first force.