If I'm not mistaken, modern EX flashes have that capability too. It can be useful when you want to override ETTL mode's tendency to treat all flash as fill. But IIRC, it's not exactly obvious how to select that feature. (It's not as straightforward as switching between manual and ETTL, for example.) You have to read the manual carefully.
Lap belts alone are not enough! Millions of family vehicles are equipped with unsafe lap-only rear seat belts. Yet retrofit shoulder restraints are unavailable or extremely expensive. With EZ-On's 86Y Car Cam Conversion Vest, your back seat passengers will enjoy the same level of protection as airline pilots and race car drivers.
Please note: While the 86Y Car Cam adds an extra level of support and safety for passengers, it is not recommended for children who chronically or aggressively elope from their seat belt during car travel. For those situations, we recommend the EZ-On Adjustable Vest for Family Vehicles.
A lap/shoulder belt can also be used with a locking clip with the 86Y universal harness When installing the 86 Y Harness, check your manual before installing. A 45 angle is the most appropriate for a tether anchor installation. Tilt locks lift to help shorten and lengthen the harness for the correct fit.
Please read the owners manual for pre-drilled anchor points, so you can install the E-Z-ON 86Y tether kit for your harness