The lightweight aluminum alloy material is durable and improves the overall performance of diff cup. Aside from the great looks, steel will not flex as much as plastic under stress or during high ambient temperatures. Compatible with Arrma Series. ARA7617V2 1/7 FELONY 6S BLX STREET BASH ALL-ROAD MUSCLE CAR RTR ARA7615V2 1/7 INFRACTION 6S BLX V2 ALL-ROAD TRUCK RTR ARA109011 1/7 LIMITLESS ALL-ROAD SPEED BASH: ROLLER ARA106058 1/7 MOJAVE 6S BLX 4WD BRUSHLESS DESERT TRUCK RTR ARA7604V2 1/7 MOJAVE 6S V2 4WD BLX DESERT TRUCK WITH SPEKTRUM FIRMA RTR ARA106040 1/8 KRATON 6S BLX 4WD BRUSHLESS SPEED MONSTER TRUCK WITH SPEKTRUM RTR ARA8608V5 1/8 KRATON 6S V5 4WD BLX SPEED MONSTER TRUCK WITH SPEKTRUM FIRMA RTR ARA106044 1/8 NOTORIOUS 6S BLX 4WD BRUSHLESS CLASSIC STUNT TRUCK WITH SPEKTRUM RTR ARA8611V5 1/8 NOTORIOUS 6S V5 4WD BLX STUNT TRUCK WITH SPEKTRUM FIRMA RTR ARA106060 1/8 OUTCAST 6S BLX 4WD BRUSHLESS STUNT TRUCK RTR, 10TH ANNIVERSARY LIMITED ARA106042 1/8 OUTCAST 6S BLX 4WD BRUSHLESS STUNT TRUCK WITH SPEKTRUM RTR ARA106048 1/8 TALION 6S BLX 4WD BRUSHLESS SPORT PERFORMANCE TRUGGY WITH ARA8306 1/8 TLR TUNED TYPHON 4WD ROLLER BUGGY ARA106046 1/8 TYPHON 6S BLX 4WD BRUSHLESS BUGGY WITH SPEKTRUM RTR ARA8606V5 1/8 TYPHON 6S V5 4WD BLX BUGGY WITH SPEKTRUM FIRMA RTR