How to Install the 399 Series Restrictor

Here are some simple steps to install the 399 Series restrictors into a -3 or -4 hose-end. Step 1 Disconnect your hose-end from the adapter.  Select the correct size restrictor: -3 (399-03) -4 (399-04) Step 2 Take the restrictor and insert into the hose-end until it seats.  Take care that it doesn’t fall out. Step 3 Connect the hose-end back to the adapter and tighten as per normal.  The hose is now ready to use with the 1mm restrictor.