Viva La Cloud - El Thunder 20700 (Stack Add On) Viva La Cloud Brass - $25.00 Gray - $30.00 This variant is currently sold out Viva La Cloud 20700 Stack Adapter, is an add-on for all you cloud chasers or trickers that require dual batteries in your 20700 mod. MSRP: $50.00 (Brass) $60.00 (Grey)