Looking for very small combination lock

First of all, Hi everyone!
My wife and I are very new to Chastity device usage so as you may expect we are fumbling just as much as we are learning currently.
She has me in a Mature Metal device and yes it fits like a glove...albeit a small evil little glove.
We would like to use a combination lock at times due to the fact that I am a pilot and away from home a lot. (I fly a private jet so no metal detector issues for me).

Does anyone have a reccommendation for a small perhaps three digit combination lock that is relatively well made and hopefully won't fall apart too quickly.
We are trying to adhere to our rule that I am NOT to have a key. We have spare keys to my cage hidden in our cars just in case etc etc. However a combo lock would be awesome.

Thanks

Chris

 

We took the Tamper evident sealed key advice. My wife made a laminated pouch of sorts using a picture only she has copy of. I have no way to reproduce the image onto another pouch so she would know at once if I were involved in any shenanigans. hehe

I did look with her on Amazon and I checked a couple airport shops but all the locks were pretty substantial in size. I think the TSA compliance criteria, demands a locking system that just simply takes extra space. By that I mean, the TSA compliant locks all seem to have a system for the owner of the lock to know if the TSA opened it or not...and that system requires extra space that increases the overall size of the lock itself.

I am not sure who is teasing who though. I just returned from a stay in St Maarten. (My employer has an estate there and we spend a great deal of time on the island). My wife wanted pretty much one thing...the cage off and I mean off before we got out of the airport parking lot. lol She anticipated this when she left home to come pick me up. Lets just say that I think we are going to go through a lot of "emergency" laminated key holders because before we were out of the parking lot, she had ripped open the laminated key pouch and the cage was sent on a journey into the back seat of the car to be found...later. The good news, She managed to allow me to take her edge off before I was able to relieve my own pressure so she managed to find her resolve in time to stop things before I could go over the edge. Like I said in the beginning though, I am not sure of who is teasing whom. I think having me in the cage is as much if not more of a tease for her than me sometimes. A combination lock would, I think save her from having to make new "emergency" key pouches as often. lol I think perhaps I will make the suggestion again and see what she wants.