The series consists of unified entertainment systems that function as both multi-tuner DVRs and 4K streaming players. Because TiVo has largely shifted focus away from retail hardware, these units are primarily available as renewed or used items from specialized retailers like WeaKnees and marketplaces such as eBay and Mercari . Key TiVo BOLT Models Review: 2018 TiVo Bolt OTA DVR for Antennas & Cord Cutting