This half face mask from TMC is exactly what it says on the tin, donning it on ones face it covers the lower portion only designed to be used in conjunction with a separate item for eye protection such as goggles or ballistic safety specs.
The mask clips on with buttons to itself and also has an elasticated cord that can be tightened as required for a secure fit.
Unlike TMC other models, this type has no wire mesh but is instead purely soft fabric in composition. With fabric webbing inside and nylon weave outside it straps on an tightens down onto the face in a minimum profile fashion hugging much closer then a wire mesh setup.
Although BB strikes can still be felt through such fabric, with its density it will take the edge of and help prevent broken skin and damage to teeth. As it is fabric and not mesh, BB fragments cannot pass through it and as it is soft BBs are unlikely to fragment anyway.
Solid mesh masks also have a habit of interfering with weapon operation as it can mess up a proper cheek weld when aiming which makes using scopes a very tricky business. A low profile fabric mask like this allows a proper positioning of the cheek allowing proper posture and easier use of optics.
It will also offer minimum disruption to wearing goggles as well. For those that are particularly paranoid, you can wear a hard solid or mesh mask over the top for general protection and then wear this fabric one underneath as a backup guard against fragments and the like. This mask really is that low profile.
Its diminutive size and weight also make it much easier to pack and store; the mesh masks are harder to fit in bags and can warp/bend when packed tight but a mesh mask like this is little more logistically challenging then a glove.
Do please note that this mask only covers the lower face (nose, mouth, cheeks, chin) and as such you will need a separate item to protect your eyes (not included).