HP C4788A 3000 Sheet Stapler / Stacker. Compatible Printers for the HP C4788A Colour LaserJet 8550, 8550dn, 8550dn Plus, 8550gn, 8550gn Plus, 8550mfp, 8550n, 8550n Plus; LaserJet 8100, 8100dn, 8100mfp, 8100n, 8150, 8150dn, 8150hn, 8150mfp, 8150n; Mopier 320.
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