Saflip® coin flips are the finest quality coin storage envelopes we know. They are inert and safe for long term storage. We offer these holders in two sizes (2 inch and 2-1/2 inch), in factory sealed packets of 50.
Professional coin grading services like PCGS often require coins be sent to them in 2-1/2" Saflips. (If you need just a few, then buying them 10 at a time is economical.