Hi, thanks for your question. According to the datasheet of Cisco C6880X, it does not have a 40G port. In addition, please tell us the specific board model of the Cisco C4500 so that we can answer your doubts more accurately. By *** on 02/27/2019

Besides the price advantage we have compared to branded transceivers, FS.COM compatible transceivers also maintain the same performance and reliability. To satisfy our customers' needs of high performance, all of our transceivers are tested multiple times in mainstream original brand switches in our test center before shipped out. By В***в on 06/07/2017

Sorry, 40G QSFP+ transeivers that operate at an industrial temperature range are currently not available, but in development. Please stay tuned. By M***a on 03/17/2018

No, it can't. To work on 40Gbps data rate, it is recommended to link the transceiver in both connectors with a LC duplex MMF fiber cables since the 40G QSFP+ BiDi Transceivers have two 20Gbps channels, each transmitted and received simultaneously over two wavelengths on a single MMF link. By M***a on 03/09/2018

As for customized transceivers, FS.COM offers regular custom choices such as compatibility, transmission distance, operating temperature, label pattern, label colors and etc. What's more, FS.COM welcomes any inquiry for customized products and solutions for all need and specifications. By B***t on 07/15/2017

On one hand, the FS.COM 40G QSFP+ transceivers with LC interface are used for long-distance transmission over single mode fiber, and those with MTP®/MPO interface are utilized for short distance transmission over multimode fiber. On the other hand, for the FS.COM 40G QSFP+ transceivers with LC interface, they cannot be split into 4x10G as they use 4 wavelengths on a pair of single-mode fibers and do not lend themselves to “splitting” into 4 pairs without substantial complexity to split out the wavelengths. For the FS,COM 40G QSFP+ transceivers with MTP®/MPO interface, they can be used in 4x10G connectivity via an external 12-fiber parallel to 2-fiber duplex breakout cable, which connects the 40G transceiver to four 10G optical interfaces. By A***o on 06/05/2017

FS.COM has been maintaining adequate stock level of the 40GBASE-SR Bi-Directional QSFP+ transceivers in U.S. warehouse, EU warehouse and CN warehouse. As long as the products you order are all in stock, we will ship them out the same day you place your order. As for some specific products or products that have a short stock, we will keep you informed ahead of time before you place your order. By B***r on 06/03/2017

The 40G BiDi transceivers use LC connectors while the QSFP+ SR4 transceiver uses MTP®/MPO connectors. Therefore, all of the existing 10Gbps MMF cables can be reused, resulting in zero-cost cabling migration from 10G to 40G. Therefore, the 40G QSFP+ BiDi transceivers are cost-effective solutions in scenarios like data centers where require short-reach, limited fibers and saved operation space of 40G connectivity. By J***y on 05/24/2017

The FS.COM 40GBASE-SR Bi-Directional QSFP+ transceivers use duplex fiber patch cables with LC/UPC connectors and support OM2, OM3 and OM4 multimode fibers. By B***k on 05/12/2017

No. Network equipment manufacturers do not require that you use only name-brand optics. In fact, when a product fault or defect occurs in the network, and the fault or defect is not attributable to the use of third-party optics, they will continue to provide support for the affected product under warranty or covered by their support program. By M***n on 04/12/2017