I used them last year and may get them again there is a rebate I think $20 or $15.
I did find an engorged tick, called them and they told me because ticks are so hardy there is no 100% protection. I live in a tick infested area, overall I was somewhat satisfied. I feel it's better than using spot on treatment.
Apache - Shiloh Shepherd 12/15/02
Kiya - Shiloh Shepherd 5/15/04
Lakota - WGSD 1/13/10