Dial-Activated Headlamp. Extremely glove friendly and intuitively used, the Princeton Tec Sync is operated via dial-activation. This headlamp bypasses button pressing sequences by turning the dial to switch between modes quickly and simply and eliminates the need to remove gloves. This light offers three modes, including a red beam for preserving night vision and a dual white mode for an even stronger light output that combines both its flood and spot beams.