The OilSafe® Grease Fitting Protector in Mid Green – size 1/4" (6.3mm) (SKU: 291005) is a contamination-blocking, color-coded cap for most standard 1/4" (6.3mm) grease (zerk) fittings. Mid Green enables visual assignment for lube, machine, or route. Each protector features a recessed head for snap-in labels/lens (sold separately), a firm-sealing fit, and is made from rugged, industrial-grade material for repeated use. Supplied in bags of 100.