Bikase

This grocery bag can be collapsed and expanded easily to carry all of your supplies.

Carry your belongings securely in the Bikase Dairyman basket. Rear rack mounting system secures basket to most common rear racks (rear rack not included)
Spring-loaded mounting system
Removable mesh netting
Dimensions: 13 x 10 x 7 in
Maximum capacity:

This basket is inspired from a milk crate and can fit any rack.

This milk crate inspired basket is great for those who want a basket that is easy put on and can be taken off easily.