Abstract: A magnetic transmission structure for a laser level includes a driving member provided with two opposite first chambers in each of which is fitted a magnet, a driven member provided with two opposite second chambers arranged in alignment with the first opposite chambers, each of the second chamber being provided with a magnet, and a motor having an output axle drivingly connected with an intermediate portion of the driving member, whereby the driven member will be rotated with the driving member without direct interconnecting members when the motor is turned on.

Abstract: A stackable transmission shaft includes a plurality of cylindrical members each having a top formed with a diametrical projection, a bottom formed with a diametrical recess, and a center formed with an axial through hole, the projection having an inverted V-shaped top and the diametrical recess being configured to receive the diametrical projection and arranged to make an angle of 90 degrees with respect to the diametrical projection.

Abstract: A safety receptacle includes a casing having a top formed with two slots, a pair of rectangular slides arranged within the casing in opposite directions, each of the slides having three sides formed with a plurality of semi-circular projections and another side with a resilient member, each of the slides having a first opening formed with an inclined shoulder and a second opening formed with a flat shoulder, each of the slides further having at top formed with a plurality of protuberances and a bottom formed with a rib, and a bottom cover configured to engage with a bottom of the casing and having a supporting portion for supporting the slides, whereby the safety receptacle can be easily manufactured and assembled.