A memory circuit, such as an embedded DRAM array, stores information as groups of bits or data using information coding in storage and retrieval data, instead of each bit being stored separately. Two guiding and locking bolts are separately located at and projected from an outer side of a center of the two recesses to engage with long slots on two adjusting slides, so that the adjusting slides are slidably located in said recesses. The released carbon also prevents accumulation of metal residue in open fields. The system is a lightweight and reliable apparatus that is easily transported and operated by a worker to secure the worker to an elevated structure such as a cargo container in order to conduct work in safety.