Chastity device discussions and reviews discussion

I notice many tiny metal gadgets that use either a stealth internal lock mechanism or one with a screw closure. I really desire one of these, but those specific locks don’t appeal to me; I’d prefer just an opening where an external padlock can be attached. However, I haven’t been able to locate this type anywhere yet. Does anyone know of devices that fit this description? Metal construction, compact size, and compatible with a lock. Preferably not overly pricey.