The Pro Trek F20 is an Android Wear 2.0 watch designed for the outdoors. It is a niche product, and has been superseded by the F30, but at £157.50 it offers great capability for the money. The offer code 10SEP19 is for "an extra 10% off the Discount Card Price" on everything at Go Outdoors and is valid from 20-31 Aug. A Discount Card costs £5 for a year and you have to get the card in store. If you already have a card, you can buy online or in store. Lots of stock at the time of posting.
If 10SEP19 doesn't work, please try code ENGHV2. Many thanks to @sneakypez
for highlighting this alternate code.
There is a post from July
for this watch at Go Outdoors, but that was before the extra 10% discount was available to all with a Discount Card, so I have added this as a new deal at the lower price.