Check the listing for details. Estrotect Heat Estrus Detector Patches 50ct Yellow AI Breeding Cattle EstroAlert. Condition: New. Listed at 79.97 USD. Estrotect Breding Indicator, Yellow color, 50ct package. ESTROTECT™ Heat Detectors are self-adhesive heat detection tools proven to help dairy farmers and beef ranchers determine when their animals are at the maximum opportunity for pregnancy. ESTROTECT™ Heat Detectors are applied halfway between the hip and the tail head spaced perpendicular to the cow’s spine. As more mountings occur, more of the highly visible fluorescent coloring will appear. More rubs = More Mountings = Maximum Opportunity for Pregnancy ESTROTECT Heat Detectors are available in highly visible fluorescent colors – Red/Orange, Green, Yellow, Fuchsia and Blue. With over a decade on the marketplace and more than 25 million units used worldwide, ESTROTECT™ Heat Detectors are guaranteed to have a positive impact on your breeding program. In recent trials, ESTROTECT™ Heat Detectors showed to perform As Good As A Bull™ in determining standing heat (SDSU, 2005). Thanks for looking and have a fine day. Be sure to check out my store for more great items for you and your animals! Before you order, please verify that the address you have given eBay is correct and up to date!! Thank you!