All our plugs are constructed of Marine Grade Vinyl, with an abrasion rating of 100,000 double rubs. they are sewn with Bonded Nylon Thread being one of the strongest threads used today. The plugs are connected by a 36" long black polypropylene webbing and have a Remove Before Flight warning streamer attached for safety. As a secondary precaution all our plugs also come with a safety flag attached to each plug that can easily be seen from the pilot seat. This aids the pilot in removing the plugs from the cowling before starting the engine. Make sure to provide your aircraft information, we use this information to double check and make sure the item will work on your aircraft. We will need the following info: YEAR, MAKE ,MODEL, S/N. and Tail Number Features: Single Engine Cowl Plugs 12" Remove Before Flight Streamer 2 Safety Warning Flags FREE Pitot Cover (Blade Type, or Booty Type) FREE Embroidery (White or Black Font) *Orders requiring custom embroidery will require an additional 2-3 business days to ship.