3M makes “small,” “tiny,” and “micro” size refill strips. Amazon and Staples should carry them. Small Refill Strips measure approximately 0.625" x 1.813" (W x L), which will fit a lot of sensors. The pack of 64 comes out to about $.16 each.
I like the thinness, The durability, and the simplicity of using these, but if you can find a roll that would work for you that would probably be less expensive.
Only buy the ones sold by Amazon itself, there are unfortunately quite a few counterfeits out there as you’ll see from the reviews. but the ones sold by Amazon itself should be fine.