Dale Fricke Holsters has a Seraphim© RMR Appendix Carry AIWB Holster for a 320 with RMR sight. From what I could find the Romeo is the same length and only .1 inch taller and wider. I emailed Fricke and he said he could make his holster work so I ordered one. I like it because from the photos it looks like the holster protects the sight. Haven't gotten it yet and my 320 ias at Sig anyway, so I can't say for sure if I'll like it. A company called Multi Holsters has an Inside the Waistband Holster made for a 320RX and 320RX Compact. If the Fricke holster doesn't work for me I'll try that one. Multi Holster has a fairly long production time. I don't know anything about either company other than I found them through a search.