From Halopedia, the Halo wiki
Skinners are long, thin tube-shaped explosive charges that that are known for their temperamental qualities. The charges use simple physical detonators instead of digital computer pads so that they cannot be hacked, likely making use of radio transmissions to detonate the explosive. A skinner must be activated manually before its detonator can be used, and it cannot be deactivated once active. When a skinner is activated, its white status light turns red.
The combined explosive force of eight skinners had more than enough power to destroy a Type-47A Scarab, disable a Covenant dome shield covering multiple city blocks, and cause vibrations strong enough to collapse much of an extensive underground service tunnel and bomb shelter system.
During the Covenant's attack on Meridian, a UNSC force led by Spartan-III Owen-B096 used skinners to great effect against the Covenant as they searched the town of Brume-sur-Mer for a Forerunner artifact.
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