6GK5991-4AC00-8AA0 SIEMENS ⍾ 6GK59914AC008AA0

SCALANCE X accessory; Plug-in transceiver SFP991-1; 1x 100 Mbps LC port, optical; multimode glass up to max. 5 km (with OM2++ fiber)

SCALANCE X accessory; SFP991-1LD; 1x 100 Mbit/s LC port, optical; single-mode optical up to max. 26 km.

SCALANCE X accessory; Active plug-in transceiver SFP991-1A; 1x 100 Mbps LC port, optical; multimode glass up to max. 5 km (with OM2++ fiber)