Oregon Type 91 PX Chain 57 Drive Links. Low kickback low vibration chain. Ideal for homeowners and occasional users. Gauge 0.50 1.3mm. Fits various saws; ALPINA, BLACK AND DECKER, BOSCH, CHALLENGE XTREME, DOLMAR, ECHO, HITACHI, HOMELITE, HUSQVARNA, JOHN DEERE, JONSERED, LANDXCAPE, MCCULLOCH, RYOBI, STIHL. Dependant on manufacturer's specifications, current guide bar and chain.