I too have inquired ( by reading other's statements ) as to the size of the entrances. I ended up using my 22 inch, 14 bar TBH nucs ( I like to multi task my equipment ) that have a hole 1 1/8 inch diameter for the main entrance, they also have a 3/4 inch hole on the side for when I put in a divider and use them for twin mating nucs. Most advice I had gotten from the bee gurus was about a 1 3/4 inch entrance being preferred by the bees.
I had real good luck so far this spring, out of seven traps I caught three swarms, guess which hole they used, yep, bees being bees they didn't read the script, all three used the 3/4 inch hole for their entrance. I also had several four feet TBH that had been divided into four mating nucs standing empty in a bee yard, all were the same except one that had two 1 1/8 inch holes on the end that I had screened over, that's the one they picked, it also had a 3/4 entrance, I think the Amish guy knows what he's doing, with the extra screened ventilation in the bottom.
I had real good luck so far this spring, out of seven traps I caught three swarms, guess which hole they used, yep, bees being bees they didn't read the script, all three used the 3/4 inch hole for their entrance. I also had several four feet TBH that had been divided into four mating nucs standing empty in a bee yard, all were the same except one that had two 1 1/8 inch holes on the end that I had screened over, that's the one they picked, it also had a 3/4 entrance, I think the Amish guy knows what he's doing, with the extra screened ventilation in the bottom.