The grease fitting is used in a bearing.
uxcell 304 Stainless Steel Straight Grease Fitting M10 x x 1mm, Silver
uxcell 304 Stainless Steel Straight Grease Fitting M6 x 1mm Thread x
uxcell 15pcs 304 Stainless Steel Straight and Angled Grease Fitting M10x1mm Metr
Brake Hose Extension Stainless Fitting 304 Stainless Steel Ultra-short 3.5cm
Brake Hose Extension Stainless Fitting 304 Stainless Steel Threaded Connection
40Pcs 304 Stainless Steel 1/4-20 UNC Car Flat Head Rivet Nut Insert