Not sure what size he uses but I like the large ones. Bought small too, but they break so easily from tension when folding them out.
There are a few sizes but this was the brand if I remember correctly: GIBSON HOLDERS 3PL Display Stand with Clear Base, Large, White, 12-Pack https://www.amazon.com/dp/B00NEDHN5U/ref=cm_sw_r_cp_api_fabc_lzhUFb3GVTMHQ