1/8" Automatic Hygroscopic Air Vent

I really like this little vent. My system uses vents like this except they require a screwdriver to open and won't vent unless you open them. These vents allow me to open them with my fingers. The automatic venting feature requires that you replace the disk periodically. I probably won't do that and won't use that feature, but even so these are easier to use than those that require a tool.

Installed 12 of these on panel rads two years ago. They work as described, but one of them cracked internally and caused a major leak onto the floor. Caleffi was unable to tell me why it had happened. In the process of changing out the others to avoid another leak, I found two others had also cracked but not leaked. i'd recommend you tighten the valve cap just barely enough to get them not to leak. I had turned them just snug, but I think the repeated heating/cooling cycles had eventually cracked the outer valve rings.