For a DVR, that's it: no glitches and enough for a long time. Buying a memory card for a DVR is the very case when the miser pays twice.
32GB High-Speed Micro SDHC Card - Class 10 UHS-I Compatible Memory Card for SD Devices
63 Review
Memory card Samsung microSDXC 256 GB Class 10, V30, A2, UHS-I U3, R 130 MB/s, adapter to SD
50 Review
💾 Transcend 16GB SDHC Class 10 Flash Memory Card - High Speed Performance and Reliable Data Storage
36 Review
SmartBuy Classic Series microSDHC 32 GB Class 10, R/W 25/30 MB/s, SD adapter
41 Review