The delay cutter is an important recovery tool that cuts the parachute cable on the rocket boosters as they are returning to earth. It does this with a pyrotechnic triggering mechanism that initiates the timed cutting sequence. There are a series of parachutes that are deployed in a sequence and some are cut to allow the following series of chutes to deploy. You can see the guillotine cutter in the opening where the cable ran through before being activated. It's something like a super charged cigar cutter that can slice through steel cables.

This is a flown piece of hardware and is marked with red paint after flight to indicate it is not to be reused. It also includes a piece of the parachute cord that it cut off.

Measures: 8.5” x 2”W x 1” D