From Halopedia, the Halo wiki
A holorecorder was a small holographic device holding various recordings.
Fernando Esparza owned a holorecorder containing a message from his deceased wife and daughter with his daughter singing to him. During his six months stuck aboard Echo 216 following the apparent destruction of the UNSC Infinity, the recording gave him a small sense of comfort. However, his repeated use of it caused the device to run out of power just before Esparza encountered the Master Chief.
After the Pelican's batteries were recharged by the fusion reactor in the Master Chief's armor, Esparza was presumably able to recharge the device. It fell into the hands of Blademaster Jega 'Rdomnai after he captured Esparza in order to lure the Master Chief to the House of Reckoning to fight Escharum. As the Master Chief fought his way through the Banished base, 'Rdomnai activated the device and placed it within a structure on the third level as part of a trap. The Master Chief retrieved the holorecorder, but it gave 'Rdomnai the opportunity to trap the Spartan within the structure using a security barrier and attempt to kill him. The Master Chief was able to slay the Blademaster and continue on to rescue Esparza to whom he presumably returned the holorecorder.
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