Half Mask Respirator. With its UniBond over-mold facepiece, AnthroCurve™ face seal, and low profile design, the Advantage 420 Respirator is the superior option for respiratory protection. The over-mold facepiece and face seal ensure the unit provides an excellent fit and comfort to the wearer. The unique yoke and harness design (patent pending) allows a user to easily don and doff the state-of-the-art respirator while maintaining a customized fit. Other features include a ComforTop headband, a built-in moisture release chin cup hole, and the extra-wide head and neck straps.