Numbers 1:9

לִזְבוּלֻן אֱלִיאָב בֶּן חֵלֹן

Of Zevulun, Eliav the son of Cheilon.

In the Torah, the name Cheilon is written what’s called chaseir (lacking) – ches-lamed-nun, without a letter vav to indicate the “O” sound. Onkelos renders the name malei (full) – ches-lamed-vav-nun. The significance of this? Absolutely none. It would appear to be nothing more than a transcription error on the part of copyists.