When using a device such as a syringe filter and a chrom syringe which both have luer slip connectors on them, the syringe filter device will simply slide onto the tip of the syringe. If it is applied properly (fully placing the device onto the tip of the syringe and a quarter turn while applying forward pressure), the connector will fit snugly on the tip. It will fit and is adequate most of the time, however it will not lock on as a luer lock connector does.
A luer lock type connector uses a twisting motion for locking the device on to the syringe with the unique connect. The “wings” of the syringe filter will screw into the luer lock connect and is fixed upon the tip of the device and does not have the ability to slide off as a luer slip connector may. This locking mechanism makes the device safer for use with liquids that provide high back pressure.