A load handling device for use in a storage system comprising a grid frame containing a plurality of stacks of containers, the load handling device being configured for being arranged above the stacks of containers and the load handling device being capable of lifting a container from a stack and moving the container laterally to another location, wherein the load handling device comprises two sets of wheels (116, 118) for supporting the load handling device, on rails disposed above the grid frame, above the stacks, the two sets of wheels comprising a first set of wheels for engaging with a first set of rails to guide movement of the device in a first-direction, and a second set of wheels for engaging with a second set of rails to guide movement of the device in a second direction, wherein one or both sets of wheels (116, 118) are configured to be raised and lowered with respect to the other set of wheels (116, 118), characterised in that the load handling device includes a container-receiving space into which the container can be lifted, the container-receiving space being arranged beneath a vehicle module, in which components such as power components, control components, drive components and lifting components are housed, and wherein one or more wheel lift motors or other wheel lift devices are housed in the vehicle module for raising and lowering one of the sets of wheels (116, 118) with respect to the other set of wheels (116, 118). the load handling device being configured for being arranged above the stacks of containers and the load handling device being capable of lifting a container from a stack and moving the container laterally to another location, wherein the load handling device comprises two sets of wheels (116, 118) for supporting the load handling device, on rails disposed above the grid frame, above the stacks, the two sets of wheels comprising a first set of wheels for engaging with a first set of rails to guide movement of the device in a first-direction, and a second set of wheels for engaging with a second set of rails to guide movement of the device in a second direction, wherein one or both sets of wheels (116, 118) are configured to be raised and lowered with respect to the other set of wheels (116, 118), characterised in that the load handling device includes a container-receiving space into which the container can be lifted, the container-receiving space being arranged beneath a vehicle module, in which components such as power components, control components, drive components and lifting components are housed, and wherein one or more wheel lift motors or other wheel lift devices are housed in the vehicle module for raising and lowering one of the sets of wheels (116, 118) with respect to the other set of wheels (116, 118). the load handling device includes a container-receiving space into which the container can be lifted, the container-receiving space being arranged beneath a vehicle module, in which components such as power components, control components, drive components and lifting components are housed, and wherein one or more wheel lift motors or other wheel lift devices are housed in the vehicle module for raising and lowering one of the sets of wheels (116, 118) with respect to the other set of wheels (116, 118).