These black plastic foundations are a strong and durable alternative to bees wax foundation. There are many benefits of using plastic foundation over the tradition wax including: It is very durable and less likely to be damaged when scrapping with a hive tool because it can be used over and over it is more cost effective wax moth and mice can not destroy it can be stored at any temperature no blow out when extracting the honey wire and eyelets are not neeeded as these foundations are designed to fit snuggly with a grooved top and bottom bar. Overall dimension of the individual foundation is 16 3/4" (W) x 5 9/16" (H). These Medium foundation are designed to fit with a grooved top and bottom bar. Note timber frames shown in images are NOT included. The plastic foundations come in the option of unwaxed or pre-waxed with beeswax. Save yourself time by buying the pre-waxed or select unwaxed if you prefer create a closed loop of wax within your hive by rendering and using your own beeswax on the foundation. For best results the unwaxed plastic foundation should be coated with a thin layer of melted beeswax on the surface prior to putting them in the hive.