Yes, it does. This is an outstanding SMB, great for deco diving. Very well made. Only downside of the OMS SMBs is that they're extremely hard to rinse. They have some fancy internal bladder system, which makes them perform great in the water but a bit of a hassle to rinse. But I would definitely recommend this one over others. The only problem I've been running into with a yellow emergency SMB is that in the US, people do it backwards compared to the rest of the world, where yellow is for "emergency" and orange is for a deco stop. I have to always explain that I follow this protocol and NOT the US protocol, which regards an orange SMB as the emergency buoy. At least in the Southwest and in California I have encountered this. But of course that is not a manufacturer-related issue. But if you decided to go with a yellow SMB without any writings on it, you may be more flexible in this regard.
I mean does it have a valve (like the one on the bc) that opens to release the exces of air that build up to avoid it from exploding?
Yes, as I said, this SMB does have an Overpressure relief valve. It's located near the bottom of the buoy. You can't see it in the picture because it's on the back side. It has a pull cord attached to it. Now mind you, this is NOT a liftbag and can't be used as such, because the OPV is located on the bottom end and not on the top end. This SMB is designed to be shot from depth and stay inflated on the surface. It is NOT designed to be deployed as a liftbag and you cannot release air once you let go.