Abstract: A locatable slab assembly for overlying a manhole cover located beneath a lowermost surface of a pavement. The locatable slab assembly includes a slab body, a tubular member, a protective plug, and an electronic marker. The slab body is deposed to permit a central line of the slab body in line with a center line of the manhole cover. The electronic marker is configured to permit a region of the pavement in alignment with the center line of the manhole cover to be located. The locatable slab assembly together with the pavement thereon can be lifted to permit access of the manhole cover.

Abstract: A multiple-layer shelf assembly includes a plurality of shelves. At least one support member and multiple engaging members are connected to each other to support the shelves. The at least one support member has at least one ridge and notches are defined in the at least one ridge. Each of the engaging members is a bent tubular member. The at least one support member extends through the engaging members and the engaging members are engaged with the notches of the at least one support member. The shelves are supported on the engaging members.

Abstract: A multiple-layer shelf assembly includes a plurality of shelves. At least one support member and multiple engaging members are connected to each other to support the shelves. The at least one support member has at least one ridge and notches are defined in the at least one ridge. Each of the engaging members is a bent tubular member. The at least one support member extends through the engaging members and the engaging members are engaged with the notches of the at least one support member. The shelves are supported on the engaging members.

Abstract: A battery case includes a space for receiving a rechargeable battery therein and at least one contact point is connected to one sidewall of the space. A circuit is connected with the at least one contact point and a switch located on outside of the battery case is electrically connected with the circuit. A display device is electrically connected with the circuit. When the rechargeable battery is received in the space, the display device shows the user the power level of the rechargeable battery.