BudsGunShop.com - is it a noise suppresor?

NO, this a flash suppressor/compensator combination. It does not reduce the noise. Instead, it might increase the volume of gunfire to people in close proximity to you as other compensators tend to do. I hope this helps.

as others have said it is a hybrid flash suppressor/muzzle break. The primary purpose of a flash suppresor is to minimize muzzle flash (fireballs) while shooting in no/low light scenarios, as in a tactical encounter this could give away your position and if using night vision a large fireball can be blinding. The primary purpose of a muzzle break is to redirect expelled gasses to reduce muzzle rise and lower the shooters felt recoil, this in turn helps you to stay on target and make faster, more accurate follow up shots, but also with the redirect of the gasses makes quite a bit more directional noise so it will make the shots louder.
A hybrid/crossover muzzle device like this one reduces or eliminates the fireball, and acts like a muzzle break without being as loud as a dedicated myzzle break ( you will also not get the same level of recoil reduction, but 223/556 is a relativelyow recoiling caliber) so while not a silencer it will definitely be quiter then a straight up muzzle break.

It is just a flash suppressor, and can reduce muzzle rise when firing a round.

no it just reduces muzzle flash

Esmaralda, no, it reduces muzzle Flash and Jump as it is a Compensator. To reduce sound away from the shooter you need a Linear Compensator that directs sound toward the target : budsgunshop.com/product_info.php/products_id/712016458/ultradyne+556+athena+linear+compensate+1%2f2x28

No, it just reduces muzzle flash and should have little to no effect on sound.