I use these gloves 5 days a week during water aerobics.  They are an injury free way to improve the strength and tone of your arms, because they allow you to move naturally, but add just the right amount of resistance.

Double neoprene gives warmth, resistance and durability.

I bought 2 pairs of gloves, one for myself, the other for a friend. Since you do not give sizing charts, I had to guess. I bought a Med. and a Lg. I use the large. It is too big but I would rather have that than too small, so I have kept them.
I suggest you make a sizing chart where people may measure across their palm.

Bought these for a friend since I was ordering other things. As far as I know they fit.

Took me a while to get used to these over just regular paddles, but now I like them a lot. They give your shoulders and arms a good work out. A good alternative to the plastic paddles, in my opinion.

Gloves seem to be a bit large as compared to others i've used which limits ability to put on fins or take a drink, but they are durable and work as expected.  Size issue is not one that would stop me from purchasing again.