This product has two interfaces, a pseudo-speed device can simulate the speed of two fans. The power is less than 0.1W, does not generate heat, and is a very stable product.It works for all Antminers with PWM 4-pin Fans. Fully compatible with for Bitmain with the Antminer T9 +, T9, S9, S9i, S9j, S9k, L3 ++, L3+, L3, D3, A3, Z9 Mini, Z9, S9, DR3, and WhatsMiner M1 (M3X) series.Auto adjustment simulator speed ,1 dummy fan simulator with dual plugs.Perfectly solve the problem without plugging in the problem.Its dual chips (one plug each) artificially generate 2200~6500 Fan RPM signals back to the miner's control board. It can work under 5~36V.It is suggested to unplug the front fan and remove it from the miner so that it will not block the air flow into the miner. Plug the fan simulator into the front fan socket. The screen shot is the real world testing result.Colour: whiteMaterial: plastic + cablePackage Contents:2 x Fan SimulatorOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.