A roller chain incorporating the roller bearings wherein a plurality of rollers are disposed between a roller that functions as an outer ring and a bush that functions as an inner ring comprises a substantially ring-shaped retainer disposed on both ends of the roller respectively. The apparatus includes a main body and a leadframe support member, and the leadframe support is formed with at least one groove for receiving semiconductor devices such that in use leads extending from the semiconductor devices lie on a surface of the support member. The core network management device automatically orders, based on the request, network elements of the access network section to perform tracing regarding the wireless terminal. The roller assembly is coupled to the threaded rod and moves linearly between a first end and a second end along guide slots when the threaded rod rotates.