Please don't apply the collar loosely, you should only be able to get 2 fingers between the collar and the cat, regardless of whether the cat goes outdoors or not. Better to avoid altogether and use other flea treatments.
Completely agree with Louie-blue's concerns, as my cats neck had become raw with missing fur where the collar was and my vet said they tell everyone to avoid flea collars for those reasons and that they are ineffective too (as I found out for myself too). Flea collars should only be used in vacuum bags/cylinders to kill fleas. Should anyone still insist on using these, please check your cats necks/fur regularly.
I always put the collar under her bed for a day or 2, I figure she'd avoid it if reacted to the active chemicals in it. Then I put the collar on very loosely. She is largely an indoor cat anyway. But I do understand your concerns.
Please don't use these collars, some horror stories about reactions to the chemicals in them. Collars themselves are very dangerous, the charity I think volunteer for advises against them altogether.
It might be the "Turkish Van"