Authentic WW2 era German manufactured K 98 Mauser front sight cover. It is spring loaded for easy and secure fastening. It also acts as a cleaning guide (the cap flips up) so as to protect the muzzle crown when cleaning the bore. It was intended for K98 rifles made prior to 1940, when front sight hoods were added, as well as for other German rifles of the period such as the Gewehr 98.  Very good condition with stick eagle waffenampt WaA63 (Mauser Werke Oberndorf AG) proofmark.