Titanium alloy mesh design Lightweight titanium alloy cross mesh provides a comfortable, breathable wear experience. The curved mesh fits closely to the shape, while the semitransparent appearance adds visual interest without sacrificing airflow. 4speed adjustable snap ring Onehanded adjustment with a rotating scale snap ring makes elasticity easy to set. It is compatible with a range of sizes and individual differences to ensure a stable, secure fit. Arc shaped smooth structure Ergonomic curved edges and handpolished surface reduce friction and skin irritation. The smooth finish makes the device comfortable for beginners and easy to adapt to. Concealed lock design Hidden lock core enhances privacy and security. It includes 2 keys for convenient storage and quick access when needed. Use scenarios Allday wear: comfortable for extended use during daily activities, thanks to breathable mesh and a secure fit. Active use: suitable for workouts or outdoor activities where airflow and stability matter. Travel or shared environments: discreet security with a concealed lock and two keys for easy management and access. Materials and performance Material: titanium alloy mesh Function: adjustable elasticity, ergonomic shape, concealed locking for privacy Compatibility: adjustable snap ring accommodates varying sizes and individual differences Security: concealed lock with two keys for reliable access and storage