Stand to hold SB-910 or SB-900 in place during multiple flash set-up. For mounting remote Nikon Speedlights when used for wireless operation, can be attached to a tripod or light stand. It is designed to hold a Speedlight in place during wireless operation, for multiple flash set-ups. The AS-21 also features a tripod socket, allowing the Speedlight to be attached to a tripod or light stand.