This product was created by Bell-A-Roma Candles. It is a great alternative to tarts and straight oil. Simmering Gel is a thick liquid made for all kinds of warmers. The liquid potpourri is super saturated with pure fragrance oil. Just pour a small amount into any warmer, when it is heated fragrance will release like no other product. Just add more as needed. The bottle is 12 ounces and has a easy pour flip cap. Available in over 100 fragrances. Case has 4 bottles. One fragrance per case.