CAPS Line Cutter
The Cirrus Airframe Parachute System (CAPS) is secured to the aircraft via 3 main attachment points (risers) after deployment. The aft riser is held in a shortened position for about 8 seconds to help the chute deploy in a predictable manner.
Once the 8 seconds are up, two line cutters with a time delay fuse will fire, severing the line holding the locking mechanism that kept the aft riser temporarily shortened.
At present, these line cutters must be replaced every 6 years (Cirrus owners take note - the 6 years is from when the device was manufactured - NOT from when it was installed in your aircraft!). Upon removal, mechanics deactivate these old line cutters by discharging them.
Special thanks to Danny and the crew at Corporate Air Center, a Cirrus Service Center at Skagit airport (KBVS) in Washington State. They have taught us a lot about how our aircraft work!