... , which are available in standard lengths up to 1 km, are ideal for testing single-mode fiber spans ... Telco and Broadband networks. Please call or email for information about other length OTDR fiber boxes and Network Simulators ... SMF-281000 m (3281 ft) x1, x2 — connectors for multimode cables, specify type (e.g. ST, SC) ... y1, y2 — connectors for single-mode cables, specify type (e.g. ST, ...