Solar Box, made with virtually indestructible HDPE marine board plastic, keeps your holes open in sub-zero temperatures. The black plastic absorbs the sun's rays giving additional heat to the box along with the plexiglass lid that lets the sun's rays shine through to also heat the box. If additional heat is needed, light the candle as an additional heat source, or you can use charcoal. Covers up to a 10" hole.
What makes this hotbox different from other similar boxes is that a small opening in the front allows you to rod-fish rather than using "hand-over-hand" with the rattle reel. The box uses a slip-cork with an extension rather than a tip-up flag eliminating any false "wind-trips". You can slip the orange whiffle ball over the extension for more visibility from longer distance.
The set of two boxes easily stack to save space in transporting and storing, just easily remove the rattle reel and candle-can from the larger box and slip it over the smaller box.
$200 for the set of two or one for $125. Less expensive and more efficient than similar boxes.