I used one of these years ago during a deployment to the Philippines during the fledgling days of JSOTF-P. The Side Zip Holster is a great, low profile, lightweight holster.
The Side Zip Holster is easy on/easy off and protects your trigger guard. However, regarding holsters, the term ‘secure’ can be relative depending on application and expectation. If you place your pistol in this holster and spend your time walking, sitting, and other regular activities you will be very pleased. But, if you do cheetah flips and swim and jump with this holster I’d fully expect to have your gat take a tumble. There’s no secondary retention on this holster at all.
Available for a wide variety of pistols from www.thewilderness.com.