if you reuse the old ones, be sure to match the tube to it's original injector.
1>1
2>2
best to examine with 20 power eye loupe for cracks and wear grooves on nose. also reverse blow out the filter in the end.
wash and reverse flush with acetone and keep clean before reinstall.
remember, a 10 micron shhitte ball in one of these is like taking a hacksaw to a rod bearing surface