The Streamlight is tough as nails but the squishy bits didn't last. My goal wasn't fancy or elegant, just to replace them and have the ability to do it again in the future.

The gasket is to protect the charging port and keep the front closed (it slides open all the time without it). This gasket works great for that. Slide it over the front then roll it into place and put a tiny bit of Super Lube on it and after a couple twists it snaps in place. After that it works great!

The button is a bit rough but, again, the goal was to protect the mechanism from dust and sweat so it does the job.