Double-stack rail transport

dual-layer Rotman lens with reduced SLL that delivers nonuniform amplitudes to the elements of a multi-beam slot array for SLL suppression Source: From

The Double Stacks slot has its own unique feature for the game that is triggered when a reel is completely filled with one kind of the 4 highest paying symbols

double lucky line slot Double Stacks

double diamond slot machine free play Double Stacks is a 5 reel, 10 payline NetEnt slot Features in this fruit machine themed slot include stacked symbols, a Double Stacks feature, a Free Spins