The 1/4 in. Grease Fitting Kit includes (8) 1/4 in. NPT straight head drive grease fitting zerks and (4) 1/4 in. 28 NPTF straight head grease fitting zerks. The 1/4 in. NPT Straight Head Drive Grease Fitting Zerk Kit is the most commonly used grease fitting at BH-USA. The push-in grease fitting is used on our flat-plate hoists, drive pipe supports, and all other products requiring grease. The simple, press-in design requires no threading to replace a worn or broken fitting. Works with any product that uses a 1/4 in. grease fitting. The ribbed design holds the fitting tightly into place. The grease gun nozzle attaches to the fitting then you can inject grease. NPT means American National Standard Pipe Thread. Made from brass material. To replace use pliers to remove old zerk. The kit includes 6 grease zerks.