The Calmark Birtcher part 40-5-10-LF-LN-M is a reliable and sturdy Gold Chem Film Wedge Lok PCB Retainer. With a 5-inch length, it provides ample space for securely holding printed circuit boards (PCBs) in place. The retainer has an expansion of 8.38mm, allowing for a snug fit and excellent support for the PCB. Made from high-quality aluminum alloy, this retainer is lightweight, yet durable. The optional lock nut adds an extra level of security, ensuring that the PCB remains in place even in demanding environments. This Calmark Birtcher part is ideal for electronic devices that require a strong and secure PCB attachment.