Rocker MF series magnetic filter holders are designed with a two-layer magnet, ensuring a tight seal between the funnel and support base around a wide range of polymer membrane disc filters. The user-friendly design allows one-handed operation and prevents possible twisting and tearing of the filter membrane. Innovative side-arm barb design on the funnel base allows a direct connection to a vacuum source tubing, or with a standard filter flask bottle via the included silicone rubber stopper. Constructed of durable Polyethersulfone (PES), the MF series filter holders are sturdy, autoclavable, and resistant to a limited range of solvents.