Yep, Empty Chamber Flag for use at the range. Ranges that require chamber flags often provide them, so I've heard.
My LCP doesn't lock open and a chamber flag would be sweet. I'll toss a weed whacker string in my bag. Great idea!
45acp, 40sw, 9mm, 38spl, 380acp, 22lr
12ga, 5.56, 30-30win
2 Chron. 7:14 Christians must seek His face