These guides will work in your atc350x, trx350d, atc 250sx, atc250es big red, trx300 utility, trx 300ex, trx 250x, and various other models.
These are NOT oversized guides that will require extensive head machining, these are stock replacements for your worn or cracked guides. However, they will need honed/polished to fit after interface fit installation
These guides are priced at $25 each to make it very affordable for even the weekend or occasional rider to properly maintained their machine.