4mm zerk fitting

Hello everyone,

I’m doing the maintenance suggestions for this machine and I’m struggling in finding a 4mm zerk fitting for the z axis. I cannot find anything online to purchase. Could somebody please link me to somewhere i can buy a 4mm zerk fitting that works? That would be greatly appreciated thank you in advanced.

uxcell Brass Straight Grease Fitting M4 x 0.7mm Thread Hydraulic Grease Fitting Accessories, 5Pcs Amazon.com