Sony's Wena Wrist straps can be attached to almost any watch out there, providing the watch face has an 18, 20 or 22mm attachment. They're designed to bring high-tech features to traditional watches, so you don't have to give up your treasured timepiece for a smartwatch.
The Wena Wrist Pro is the more expensive of the two options, and comes in black and silver.
The Wena Wrist Active is for sporty watch wearers and includes GPS tracking and heartrate monitoring.
Either you can choose to attach the strap to a watch of your own, or choose from a selection of watch faces made by Sony.
Sony's selection of faces includes mechanical, solar and quartz options.
The tech is concentrated in the clasp of the strap.
A subtle screen displays basic notifications from your phone.
When it's not displaying notifications, it isn't obvious the Wena Wrist even has a screen.
Both watch straps also allow you to make contactless payments when you're on the move.
But the Wena Wrist Sport has superior activity tracking.
You can even use the strap as a standalone activity tracker, if you'd prefer not to go running wearing a full watch.
The Wena Wrist Active comes with an easy-release mechanism to make it easy to switch between modes.