Has your Qualcast lawnmower (the ones with the grassbox on the back) stopped driving forward or making a slipping noise? The drive belt has probably worn out or snapped. This is a quality replacement V-belt that fits a whole bunch of Qualcast models: RE25, RE30, RE35, XR25/30/35, and SYSTEM 250/300/350. It's a 79-tooth belt that's a direct match for the original part numbers like T41945 and T43506. Swapping it out is usually a straightforward job if you're a bit handy – you might need to tip the mower on its side and remove a cover. Make sure your mower is completely disconnected from power before you start. Keep your mower running smoothly for another season with this simple, affordable repair part.