The JBC Tools Modular line features four control units, six stands, eight tools and more than three hundred cartridges and tips which can be combined to create a personalized set-up tailored to your needs. The DD-1B control unit features connectivity to operate two tools at once. The DM-1B control unit features connectivity to operate four tools at once. Both units feature adjustable sleep and hibernation modes and independently adjustable settings for each individual tool; all adjustments can be locked by a PIN. Also, both the DD and DM are fully connectable to all JBC tools, including both the DR and DS desoldering irons with either the MS-A or MV-A suction systems. The MS-A and MV-A are desoldering suction modules that, while the control units regulate temperature, collects the solder before it cools down. There are a wide assortment of tools, stands and accessories that are compatible with the Modular line to make your process the easiest and most effective that it can be, if you have any questions or need assistance choosing which Modular set-up is right for you contact one of our customer service representatives at 1-800-782-4487.