For me, these worked well to reduce the number of bites that I could have gotten in the summer and in high mosquito areas in the tropics for nearly a 24 hour period. (Smaller than average sized person) It was simple to apply and did not require any maintenance once it was on. Water nor my sweat did not dislodge the glue. It was clear and mostly invisible.

For a box of five packages, it was expensive. Stores do sometimes clear it out at the end of a summer for cheap with the expiry dates long in advance. For no fuss, deet free mosquito protection, this worked well for me.

Camping on the top of the lookout in Canning Nova Scotia - 3rd week of July. The mosquitoes were huge. I bought these patches at Canadian Tire. 4 in a box for $6.99. I pulled them out and asked if anyone else wanted to try these out .1 girl said no. she had to bail to her tent by 10. The rest of us cradled beers until the sun rose... Nobody that stayed awake got a bite.. Vitamin B1 patches. I am sold for life. I haven't tried them on black flies...in spring I will.