Never used them, but sounded interesting if you have a need for such a thing. I saw an ad in a 2017 magazine for it and looked it up. Still in biz, so may be legit.
Why noy just use a deep planter. I use 10 of them for like 30 hot peppers. (Or cheaper 20 gallon bag pots for $5 each)
This is what they sell locally in my garden center, maybe for $25.
Has drainage holes at bottom.
The HC Companies ROP28000E35C005LRTMU Romana Planter, 28", Clay Amazon.com
I think the main thing going on here is a “Sub-Irrigated Planter” or SIP. Main idea is to have the water reservoir at the base, a moisture wicking material up to soil and an air interface between the bottom of the soil barrier and the water at the bottom. I’ve made one out of a 5g bucket, the bucket cap, a “single-use” yogurt cup for the wicking column, a pipe for watering the base, and peat based mix. There are other plans online as well.
I have used similar planters from Home Depot, they call it city pickers and you can grab them for discounted price ($15-$20) in September. They worked really well to grow onions, and shallots.