I have six boxes of K9 Advantix Blue for dogs over 55lbs, four applications each box available for purchase. This does not require a prescription and does not have an expiration date. I am selling these for $40 a box, which includes first class postage. I bought two cases, and I can't use all I have before the end of the warmer weather. Maybe someone else would like to have them at this price. Paypal preferred. I still have some Interceptor too. Contact me privately at Cathyyak@aol.com.