Every electronic device eventually loses its efficiency due to wear and tear. If this applies to a razor, it's important to understand that the overall structure lasts much longer than the cutting elements. The Braun Series 8 83M set, consisting of a shaving grid and a cutting block, is recommended for replacement every 18 months of regular razor use. It will provide a more efficient stubble cut and protect the skin from damage. The set is only compatible with the Series 8 razor.