Screw these Third Party Pannier Adaptors into any Tailfin Rack or AeroPack ‘with Pannier Mounts’ to enable the use of other pannier bag brands. They have a diameter of 10mm so we recommend the use of appropriate pannier inserts. This item is not compatible with the T1 Rack. These adaptors are sold as a pair. Note: Although the adaptors work with many brands of panniers, not all are compatible (e.g QL3.1 System). Weight 82.5g Installation Video Guide