This item only appears in Special Stages. A glowing rope between Sonic and Tails lets them scoop up Rings. The rope disappears after a set time. 
— Description, Sonic the Hedgehog 4: Episode II
The Combination Dash is a power-up that appears in Sonic the Hedgehog 4: Episode II. It is power-up not contained in Item Boxes that is designed to make it easier for the player to pick up Rings.
Description
The Combination Dash takes the form of a blue coin with a golden edge and an icon of Sonic and Tails' right hands holding firmly onto each other
Overview
Teh energy rope between Sonic and Tails created by the Combination Dash.
In Sonic the Hedgehog 4: Episode II, the Combination Dash is a rare Item Box-less power-up that only appears in the Special Stages.
In gameplay, the Combination Dashes appear along the Special Stages' chutes and can be picked up by simply touching them. Upon obtaining one, the Combination Dash will automatically create an energy rope between Sonic and Tails that constantly changes color. Any Rings that touch this rope are automatically picked up and added to the player's Ring count, effectively allowing the player to pick up Rings that slip in-between Sonic and Tails. After ten seconds however, the Combination Dash will wear off and the energy rope will vanish.
Trivia
- The Combination Dash uses the same icon that is depicted on the Special Combination's Item Boxes.
