The Smart Troll Downrigger Kit has:

• Two Smart Troll Probes
• Two Smart Troll Paddlewheel attachments
• And everything else you need for Depth, Temperature and Speed on Two Downriggers
     * Smart Troll Receiver
     * Smart Troll Transducer
     * Smart Troll Probe Charger

With the Smart Troll Downrigger Kit you can measure Depth, Temperature and Speed on two different Downriggers. That way you can get that data at two different points in the water column at the same time. The additional information can help you determine what bait or lure you want at different points in the spread. It also helps to avoid the possibility that you missing a current because your Speed Probe is above or below the point in the column where the current exists.