C10-6BN Automotive Black Nylon Reduction Coupler, 5/8" Hose Barb to 3/8" Hose Barb (Pack of 10)

I used these adapters when I installed a catch can and they fit snug inside 3/8 and 5/8 hose. They've been in the engine bay for a month now and aren’t showing signs of wear. I used them with clamps just in case.Update: January 2020 and the adapter is still fine after more than a year of being in the engine bay. It’s survived engine oil and under hood heat.

Sturdy adapter, worked suprising well.

Good snug fit! But be sure to read the description! I needed 2 so ordered 2 and now have 18 extra!!

As expected