A good quality lightweight (only 570g) daysack with ventilated back system, and hydration system opening. Blurb from Amazon site:
* Very lightweight and comfortable hiking backpack
* Single main compartment with zip pocket in lid
* Ventilated back
* 20L Volume, Weight 570g
* Side mesh pockets & elastic cord for additional storage
and technical details from Vaude:
* Main fabric: 100% Polyamide; 210 D Dobby Polyurethane coated;
* Contrast fabric: 100% Polyamide; S 70 DL siliconized;
* Back part: 100% Polyester; 600 D Polyurethane coated;
* Lining: 100% Polyamide; 190 T Polyurethane coated
You need to select the Black colour on the Amazon site to get this price, as the other colours are £47 and £49, and the black colour is typically around £40-£50 elsewhere.
It had actually dipped to just under £22 yesterday, but it's still a cracking price.