Pet Tracker for small cats.

Looking for ideas or recommendations

We're based in the UK We use PetTracer on one of our cats (5.5kg) However the two pictured are much smaller, darker short haired cat is full grown and weighs in at 2.5kg Her kitten the lighter grey fluffy one is only 6 months (We rescued them both and yes they are both spayed/neutered now)

We do still have the old locators (now tabcat) from years ago. The Pet Tracer collar is too big on either by a fair bit.

Any other recommendations... We have android phones in the house, no Apple products to use airtags.

Thank you in advance for any help ☺️