The most interesting thing about the a-Jays One design isn't so much the ear buds themselves, which are an ordinary bud style only enlivened by the presence of sets of different-sized silicone sleeves, but the cable, which rather than the customary round, is instead 115cm of flat black cable. While the a-Jays One represents the very bottom of the rung of the ladder of Jays headphones, with prices increasing as you go up the quality scale, it's a nice feature to have at a budget price point, as it makes it very hard (but not quite impossible) to tangle up the headphones themselves.
As with other entries in the Jays line, the a-Jays One ships with a large plastic case to house both headphones and silicone sleeves. It's good for home storage, but we'd strongly argue that it's too large to realistically be carried around for terribly long.
Inside your choice of silicone sleeves lies an 8.6mm dynamic speaker with a claimed frequency range of 20-18,000Hz. Jays claims that these entry-level speakers are particularly tuned for bass frequencies. If you step up the range to the suitably named (but pricier) a-Jays Two or Three you get slightly different performance characteristics and a range of accessories including airline travel adapters, a full travel case and a stereo splitter.