Cheers. 

Yes. NEX-5T is a APS-C crop sensor. I've used these sensor cleaners on my Sony A6000. They work very well. 

Works great...I had a sticky bit of dust on my camera sensor that my Rocket Blower wouldn't remove. So I purchased this product and it worked great. I used the dry approach not using the liquid. Liquid used is a last resort 

The size is important because they are made to be used with a single swipe The sensor is not the issue it is the oils in the lens chamber and if you touch that with the swab you have ruined it and can mess your sensor up badly... if you use a smaller size one it can work but I would want a sensor loupe to see what I am cleaning up and also to make sure my swab is clean and I am not taking particles that I picked up on the 1st swipe and running that into another part of my sensor... The sensor is the eyes of your camera... Hope this is helpful. 

Oops, I'm too slow, I see now that PRG West Chester PA has already answered your question.