STEEL HAWK Tire Air Valve Caps Precision CNC Machined Stainless Steel, Extended Knurled Design Rust, Leak & Dust Proof Metal with O-Rubber Seal - Ideal for Vehicles 4 Pack-PVD Black

316L STAINLESS STEEL, NOT ALUMINUM OR PLASTIC – Solid marine-grade 316L stainless steel, the alloy used in dive watches. Heavier and tougher than aluminum caps, which corrode and can seize onto brass valve stems. NO-FUSE DESIGN THAT WON'T SEIZE – Stainless steel is far less reactive with brass stems than aluminum, so the caps still twist off by hand after a winter of road salt. PVD finishes resist fading, chipping and UV. AIRTIGHT SILICONE O-RING SEAL – A heat-resistant silicone O-ring inside each cap keeps water, dirt and salt off the valve core and adds a backup seal against slow air loss. UNIVERSAL FIT, STANDARD OR EXTENDED – Fits standard Schrader (TR) valve stems on cars, trucks, SUVs, motorcycles and ATVs. Standard sits low and flush. Extended is longer, with more knurling to grip. KNURLED GRIP, 4 CAPS PER PACK – CNC-machined knurling gives a sure grip even with wet or greasy fingers. A small, noticeable upgrade that makes a good gift for car and truck owners.