Description: 1/8 npt x 1/4 compression check valve.  Made in the USA. These all brass check valves have a  low tension spring inside, and with the spring they can be mounted and used in any position.  The light spring gives them a very low cracking pressure, in other words low fuel pressure will open the valve.  If you have need for even lower pressure you can simply remove the spring as show in the picture.  With no spring the valve needs to be installed in a vertical position so the ball falls down to seal.  Very nice and professionally made check valve.  Volume discount pricing and dealer/distributor inquires welcome. We have thousands of these check valves in stock. We have many other sizes and styles listed in our store if you need something similar. Some applications you may need to peen the bottom to prevent the ball and spring from falling out.