This simplex single-mode pigtail pairs an ST/UPC connector with a semi-tight 0.9 mm buffer that strips long lengths in one pass. That makes it quick to splice inside ST patch panels, wall boxes, and splice enclosures. The bend-insensitive G.657.A1 fiber handles tight routing with very little added loss.
It splices cleanly onto standard G.652.D single-mode cable. A yellow buffer marks it as single-mode, and the material meets the OFNR riser fire rating. Pick the 1 m length for compact boxes or 3 m for larger frames with more slack storage. Splicing crews favor this version when speed matters more than buffer stiffness.
Why Semi-Tight Saves Time
A semi-tight buffer leaves a tiny gap around the 250 µm coated fiber. It holds no gel or powder, and the gap isn't visible at 100x magnification. The payoff comes at the splice tray. Ten centimeters or more of buffer slides off with one circular cut. On jobs with dozens of splices, those saved minutes add up fast.
ST Connector Design
ST connectors lock with a keyed, spring-loaded bayonet. A quarter turn seats the 2.5 mm ferrule firmly, and the key keeps it aligned every time. Campus backbones, older telecom racks, and many industrial controllers still terminate on ST ports. This pigtail fits them without extra adapters.
Bend-Insensitive G.657.A1
ITU-T G.657.A1 fiber supports a 10 mm minimum bend radius. At a 15 mm radius, ten full turns add no more than 0.25 dB at 1550 nm. Fiber coiled in a cramped splice tray stays well within its loss budget. It also stays fully compliant with G.652.D.
Long Single-Mode Reach
The 9 µm core supports long-wavelength optics at 1310 and 1550 nm. Typical cabled OS2 attenuation runs about 0.4 dB/km at 1310 nm and 0.3 dB/km at 1550 nm. Links can span buildings, campuses, or entire cities.
Choosing 1 m or 3 m
Pick the 1 m length for small wall-mount boxes and compact splice cases, where extra fiber is hard to store. Choose 3 m for rack-mount frames and distribution panels with deep splice drawers. The longer length also leaves room to cut back and re-splice later without replacing the pigtail.
• Connector: ST/UPC, keyed bayonet, 2.5 mm ferrule
• Fiber: single-mode 9/125 µm, G.657.A1
• Fiber count: 1 (simplex)
• Buffer: 0.9 mm semi-tight, yellow
• Fire rating: OFNR
• Length options: 1 m and 3 m
Strip, clean with isopropyl alcohol, and cleave to a flat end face. A modern fusion splicer typically joins single-mode fiber at well under 0.1 dB. Protect each splice with a heat-shrink sleeve before seating it in the tray.
