I bought these on Amazon:
https://a.co/d/aFoUhOq
When I looked at them out of the package I thought they would be too short and wouldn't reach the girls tails, but they fit great. They've been on for two weeks and I check them every few days to make sure they aren't getting any irritations from the straps under their wings. So far so good.
I got these at the same time
https://a.co/d/bvSpZJH
The plastic wing covers aren't sewn on like I thought they would be so it wasn't worth the extra $1 a saddle, the boys knocked the wing covers off after a few days.
For reference the two girls wearing these are a Buff Orpington pullet and a Black Jersey Giant pullet. They aren't the calmest birds when being handled, but the saddles were still pretty simple to put on with an extra set of hands to hold them still.