The quad charger keeps batteries charged for your QL Series, RW series or P4T/RP4T mobile printers. Charges up to 4 QL Series or RW Series lithium-ion batteries at a time in approximately 2-5 hours. (UK use only.) COMPATIBLE PRINTERS – P4T – QL 220 – QL 220 Plus – QL 320 – QL 320 802.11 FH Radio – QL 320 Plus – QL 420 – QL 420 802.11 FH Radio – QL 420 Plus – RP4T – RW 220 – RW 420