LoopyDo© 2G Prewashed Inserts are the #1 insert on Diaper Pin and a favorite with cloth diapering moms worldwide. 

Made of 2 layers of thirsty hemp french terry plus 2 layers of ultra-thick white microfiber, these inserts can really absorb a lot! 

Better still, the hemp has been prewashed!  These can be used immediately and washed right away with all of your diapers!  In addition, LoopyDo© 2G Prewashed Inserts are sewn in a loop so they'll dry just as fast as anything else in your dryer.  (They will still need a few washings to achieve their full absorbancy but you can begin using them immediately.)

A Knickernappies product. 

Inserts listed here are the 2G version.  The new version is wider to fit the 2G diapers and to fit all brands of pocket diapers.

Small = 12"x5.5"
Medium = 14"x5.5"
Large = 16x5.5"