microSDHC memory cards and readers.
I backed the Dash microSD and SD Card Reader on Kickstarter in November 2015, a project that raised US$11,492 from 717 backers. I chose the US$22 reward, paying about US$25 with shipping, for a compact build-your-own card reader.
I'd always wanted a GoPro but couldn't justify the cost on an action camera I might rarely use. Then I spotted the Sony HDR-AS20 bundled with a 16GB Micro SDHC card on Amazon for US$97, a tempting pre-Black-Friday deal.
Strontium recently launched its Nitro Plus range of MicroSDHC cards. Rated UHS-1 (U3) for 4K Ultra HD recording at 3840x2160, the Nitro Plus offers write speeds of at least 30MB/s and read speeds of at least 80MB/s, in three capacities.