SureLock II replacement weight pockets are offered in 3 sizes. You must select the model that matches the original SureLock II pockets that came with your BC. 

This is the standard pocket that comes with Aqualung / SeaQuest BCD's size XS, S, M or ML.

For Size L BCD's and up choose the Double Channel pocket.

For the new Axiom and Axiom I3 you need to choose the Single Channel Long 15lb Pocket.