These are some of the products we use and have used. Currently our crew wears Seresto collars. We buy our products from Budget Pet Care and they ship from the United Kingdom. While shipping takes a bit longer, the prices are so much better and the products are real. We've been using Seresto for over 5 years. I will add some products as we go that we use. Please understand, these are affiliate links and while I make a few cents off your orders, you're not charged any extra because of it.