Snack Attack Vending LLC is offering a Selection Button Assembly Kit for Vendo soda machine models 511, 540, 576, 620, 621, 720, 721. Included in kit is button assembly, switch, sold out light & vend label holder.  If having problems with machine vending same flavor drink every time or switch does not work at all. Then that flavor switch is bad and needs replaced. This switch is located behind coin mechanism door. The selection button assembly kit is factory brand new.