I've been looking for these adapters and they are not stocked by most camera or hardware stores, nor do they cost $1. The 3/8" to 5/8" is common. However, the 1/4" to 5/8" is not. I checked with a bunch of camera stores in Atlanta and non had one, or even knew what I was talking about. B&H Photo, which stocks all kinds of pro photo and audio gear, has a 3/8" to 5/8" adapter for around $4. Dale Pro Audio has the 1/4" to 5/8" for $14.