1.Jv4 refill cartridge refill ink conveniently. 2. Clear body, can check the ink level ... see ink level very clearly,2. Big cartridge ----hold much more ink, 220ml each, neednot refill time to time.3. PP material ... is simple, just pour into ,easy work.The color 3000 refill cartridge can use for: EPSON COLOR3000/PRO7000/PRO7500, ROLAND 500/600 ...