google would be your best bet
A holly trainer substitute is the keep cage. 30$
THE KEEP Chastity Cage (Crystal) THE VENETIAN MERCHANT https://www.amazon.com/dp/B071FBXRLZ/ref=cm_sw_r_cp_apa_I.mgAbS3PQ7XY
aliexpress has a bunch of cheap ones. about 10 bucks or so
I know it’s a cliche, but the best device for anyone is whatever fits your anatomy. I’m my case, I could slip out of any device, sometimes accidentally in my sleep even, until I stretched my PA to 8g and tried a PA-5000.
That being successful, 6 months ago I was upgraded to a Mousetrap from malechastitynow.com; which I’ve been in continuously except for inspections (handcuffed) for chafing or other problems and sessions (escorted) of laser hair removal. We are confident now on the health and hygiene front. So once the laser sessions are done, the security screw will be fastened with Loktite Red “for the duration”.
Oh yes, I should have mentioned: for the mousetrap, you do have to upgrade your PA to a minimum of 4g. Fortunately, the PA5000 comes with pins for 8, 6, and 4g in three diameters each. And since the mousetrap is high-quality steel, you can have a D-ring welded onto it, which can come in handy.
Wow that sounds like a really hot lifestyle. Do you have a blog or something with all your stories?