The Multi-Function Shoe Adapter AD-E1 is designed to provide sufficient static pressure strength. This enables the AD-E1 to withstand the weight and stress when paired with large accessories like the Speedlite EL-1. Sealings at all the connecting points ensure dust- and drip- resistance capability when using existing Speedlites. Some of these include the Speedlite EL-1, 600EX series, and 580EX II, which require this adapter to maintain their dust- and drip-resistance capability on the Multi-Function Shoe.