Bmcu370C Hall buffer version, it supports bidirectional buffering, its feeding is softer and less likely to cause damage to the filamenthub. Supports the function of "long retraction when cut in filament". BMcU is an open source project. It can realize the function of -lite at low cost. This kit is currently compatible with A1, A1 mini printers and also with the P1 series (experimental). This kit can only work in 4-channel mode, which means it cannot currently support more than 4 channels via expansion. Compatibility: A1, A1 mini, P1S P1P(Experimental support), X1 Series (Possible but unproven). Attention:Assembling and debugging this kit may require some hands-on skills, such as soldering wires with a solderingiron, etc. Color:White Material:Plastic+Metal Package Contents: 1 * BMCU370C Auto Refill Farm 1 * cable 3 * Tube Only the above package content, other products are not included. Note: Light reflection 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.