The assembly of any product requires much more than great electrics. The structural side of putting things together may often be regarded as low-tech and of secondary importance but can make the difference between success and failure. Outer cases are readily available in the form of plastic and metal enclosures, as are PCB boards, but in addition to the essential electrical components, a great number of small structural and mechanical components are also needed to safely keep everything correctly located. Clips for DIN rail fitting, spacer bolts and sleeves are available in various materials, including plastic, snap-fit types for chassis to print or print to print use, and PCB holders are also usually snap-fit. Sheet materials of many types are available, as are bars, rods and channel sections. Ball bearings, castors, hinges and locks may also be needed and some equipment may need vibration dampers or pull-out telescopic slides. Nuts, bolts, washers and screws are often purchased in convenient mixed sets. These small components are essential in prototype work and equally important in the repair shop. Chains, shackles and cables are often required and specialised locks are needed for safety lock-out applications. A great many products are available, making it a simple task to choose the ideal mechanical components.