Renthal's Ultralight grooved off-road front chainwheels are chosen by more factory motocross and supercross teams than any other chainwheel on the market. Designed to offer a long lasting front chainwheel in a lightweight design which offers maximum power transfer. They are CNC machined from a cased hardened and core refined 655M13 nickel chromium steel. Computer aided CNC machining removes additional material from the chainwheel while still maintaining its structural integrity. Mud grooves are CNC machined into each tooth on both sides to allow mud to flow away from the key contact points between the chain and the chainwheel. This helps reduce wear and increases the drivetrain lifespan. Fits: KTM 125 EXC 91-11, 125 SX 03-13, 144 SX 08-11, 150 SX 09-13, 150 XC 10-13, 200 EXC 00-03, 200 EXC/XC/XC-W 98-11, 200 SX 03-06, 200 XC/XC-W 09-11, 250 EXC/XC/XC-F 02-11, 250 EXC/XC/XC-W 91-04, 250 EXC-F 02-11, 250 SX 91-13, 250 SX-F 06-13, 250 XC/XC-W 09-13, 250 XC-F 11, 250 XC-F/XC-F-W 09-10, 250 XCF-W 11-13, 300 EXC/XC/XC-W 95-08, 300 XC/XC-W 09-13, 350 EXC-F 12-13, 350 SX-F 10-13, 350 XC-F 11, 350 XCF/XCF-W 13, 350 XCF-W 12, 360 SX 96-97, 380 EXC 00-01, 380 SX 98-02, 400 EXC/XC-W 00-08, 400 SX 99-02, 400 XC-W 09-10, 450 EXC 08-12, 450 EXC/XC/XC-W 03-08, 450 SMR 06, 450 SX ATV 08-09, 450 SX-F 03-13, 450 XC ATV 09-10, 450 XC-F 09, 450 XCF/XC-W 13, 450 XC-W 09-12, 500 EXC 12-13, 500 XCF/XC-W 12-13, 505 SX ATV 10, 505 SX-F/XC-F 08-09, 520 EXC 00-02, 520 SX 99-02, 525 EXC 03-09, 525 SX 03-06, 525 XC ATV 10, 530 XC-W 09-11; Polaris 450S OUTLAW 07-09, 525IRS OUTLAW 07-09, 525S OUTLAW 07-09; Husaberg TE 125 13, FE 250 13, TE 250 12-13, TE 300 12-13, FE 350 13, FE 390 10-12, FE 450 04-13, FS 450E 04-08, FS 650C 05-08, FS 650E 03-08, FX 450 10-12, FE 501 13, FE 570 09-12, FS 570 10-11, FE 650E 03-08; Beta 250RR 05-09, 350RR 11-12, 400RR 05-12, 450RR 05-12, 498RR 12, 520RR 10-11, 525RR 05-09.