Use this waterproof outer pocket by Ortlieb for tools, first-aid-kit, bottle, purse etc. It can be mounted to any Ortlieb pannier (or to any other bag).
Fast attachment and removal is guaranteed. The loop on the reverse side allows you to wear the outer pocket on your belt or to attach it to straps.
The outer pocket is suitable for panniers and small backpacks. The outer pocket comes as a single bag and includes the mounting rails, a punching tool, and a template.