New Horizon
Guru
I tried a Endura's pak-a-jak but the zip felt very insubstantial - I could see it breaking easily. I went for the more expensive Photon instead, which is a proper waterproof and has a better (for me), ahem, 'relaxed fit'. Too early to call on its abilities but packs real small into its own bag and is about 200g - it would fit a jersey pocket or a bottle cage.