Wayne D. wrote about JBL Sealing Ring Pump Head CristalProfi e4/7/900/1 in February 2020:
Hi mate I have aqua vatil avex600 will the seal fit my filter please thanks
Aquaristikshop.com: This sealing ring is for the use with an JBL CP external filter. It's unlikely that the part fits to any other filter.
Arindam M. wrote about JBL Sealing Ring Pump Head CristalProfi e4/7/900/1 in 2018:
Does the e900 top head O-ring...fit thr e901 and 902? Also, does the e900 Impeller also fit the e901/902???
Aquaristikshop.com: The sealing ring for the pump head is the same for th JBL external filters CristalProfi 900,901,902. The impeller of the greenline filters e901 and e902 are the same.