npub17pfscp7lp6t5cfvk0lpvytzmaxpcgujm39rq4lya8mx420aemq6skdmus7 (npub17pf…mus7)
The station I'm calibrating also has a 1310 nm TLS (81600B), but it's always the 1550 that gives me problems.
Keysight doesn't even offer the 1550 in this form factor anymore, only the 81600 style, due to reliability.
It's customer owned equipment, so I'm stuck with what I've got.