The helmet adjustment accessory with a chin strap and button is an essential for ensuring your helmet remains securely in place. The BOA rotary lock allows for easy and precise size adjustments, catering to different head sizes and shapes. This accessory is great for construction sites, sports fields, and other high-risk areas where helmet stability is crucial. Its durable design ensures performance, providing peace of mind in any situation. Features - Color: Black -Material:Plastic - Size: 36.00X11.00X1.00cm/14.15X4.32X0.39in -helmet fit: the adjustable helmet regulator allows users to DIY the fit of their helmet, providing enhanced comfort and security -Effortless chin strap adjustment: the chin strap with button adjustment makes it easy to quickly and accurately adjust the fit, ensuring the helmet stays in place -Secure boa head lock: the boa rotator head lock offers a reliable locking mechanism, preventing the helmet from loosening unexpectedly -Lightweight construction: made from lightweight materials, this accessory ensures that the helmet remains comfortable to wear without adding unnecessary weight -Wide compatibility: designed to be compatible with a variety of safety helmet, this accessory enhances both safety and comfort for different users Package list: 1 x hard hat chin strap 5 x buckles 1 melt adhesive