I did some reading up on this, and it seems like it is well liked and effective. I ordered one For Wolfy at www.chewy.com for $42.99 and got free shipping since I had a few other things that I needed from them too. I like this idea better than a spot on treatment, and last Fall in NC, the Advantax II didn't even work for him. The Seresto works out to be a whole lot cheaper than Advantix too. He's not outside for extended periods of time, so I'm hoping for good results. We'll see................