The Celestron EclipSmart Solar Filter is an excellent product for observing the sun. The filter itself is very lightweight and looks fantastic on Celestron Schmidt Cassegrain telescopes. The filter does its job, blocking out 99.999% of all light it is exposed to.
My favorite feature is how secure the solar filter attaches to the telescope. It attaches to the telescope the same way the dust-cover attaches to the telescope, which provides a very safe and secure fit. Additionally it comes with Velcro straps if you want it to be even more secure.