Package Includes：You will get 2 pcs replacement ratchet knobs and 2 pcs replacement sweatbands.Sufficient Quantity For Daily Use. Compatible with GREEN DEVIL Mervex series hard hats:Knob ratchets and sweatbands are vulnerable and consumable parts,Replacement parts can extend service life of GREEN DEVIL Mervex series hard hats . Replacement ratchet knob:Two styles of ratchet knobs are available for selection.The ratchet knob on hard hat is simple to adjust hardhat from 20.5 to 25 inches, one-handed adjustment design allows workers to modify fit without removing work helmet. Replacement sweatband:hardhat sweatbands is made Premium from cotton, has strong sweat absorption and soft touch, it lets you clean and comfortable at work, improves work efficiency. Easy to install:With detailed assembly instructions and easy for replace. 1