CD-M series threaded plastic caps for metric fittings protection against ingression of dirt, moisture, and other contaminants. Made of low-density polyethylene and available in sizes from 0.55 in. high by 0.66 in. wide to 0.60 in. high by 1.05 in. wide.
Caplugs, (716) 876-9855, www.caplugs.com