dada2 output read length in rep-seqs.qzv


I do have query regarding dada2 output file rep-seqs.qza:

16s V4 region was amplified by using the PCR primers (F515/R806), and sequencing read length for both pair end read is 250bp.

dada2 rep-seqs.qzv file gives min. seq. length is 229 and max is 436. I am not able to understand it when fragment length between forward and reverse primer is 291, how it can be 436

Kind Regards

An off-topic reply has been merged into an existing topic: Training classifier against V4 region

Please keep replies on-topic in the future.