2 x Waterproof heat mats
12/12 5 PM Central: These are on sale for $22.49. Shipping is also free to many US addresses with Prime Membership [Try Prime for Free] or a qualifying order. Prices and availability can change quickly. Check product page for current info – More About Prices
Prime Exclusive: As of this posting, this is exclusively available to Amazon Prime Members. Amazon Prime has a lot of great benefits.
HYDGOOHO Seedling Heat Mat 2-Pack Heating Mat Hydroponic Heating Pad Waterproof for Seed Germination Cloning and Plant Propagation – note that multiple variations of this product may be available, as such a different version may appear at this link