These fiber optic pigtails keep the light that bounces back low, around 40 dB. Additionally, you can connect and disconnect them 500 times. The ferrule is made from zirconia ceramic. Mixing them up drives costs higher, increases loss, and slows your rollout. A decibel is expressed as the base 10 logarithm of the ratio of the power of two signals, as shown here: dB = 10 x Log 10 (P1/P2) where Log 10 is the base 10 logarithm, and P1 and P2 are the powers to be compared. The loss spec for prepolished/mechanical splice connectors or multifiber connectors like MPOs will be higher (0. 25 dB and low loss shall be a maximum of 0.