Perfect length, easily keeps soil warm in old mornings in outside hotbox.

These were just what I was looking for. First thing in the morning I stick my finger in the soil and its slightly warm at the root zone. Helped me get a jump on my tomatoes. Good price and really quick delivery.

These have worked great for me so far. My seeds are sprouting much quicker and are growing like wild fire!

If you are looking for a heating cable you can use in an indoor made seed bed this isn't for you. I installed the cable as directed on a piece of hardware cloth that matched the size of my seed bed. It's a wood box using sand as the substrate. The cable does not provide enough heat to generate warmth for seed trays sitting on the seed bed. Possibly, If I buried each of my seed tray to be on top of the cable it might work but that is not practical. I formerly used incandescent rope lights in the sand which when buried generated a nice heat fore the seed trays sitting on top. This works if the bed is in a nice cool place out of the sun. If external heat gets to the bed, the rope lights get too hot. All that said, get the instructions before you buy and be sure it's only for soil warming where you are actually planting seeds.

ACF Greenhouses: These are made for heating soil not exposed trays. We recommend our plant heating mats for trays.