OEM Duplicate Belt Replaces John Deere Belt Numbers GX20305, GY20571 Belt Duplicated to meet or exceed OEM specifications, not a generic belt. Replaces John Deere Belt GX20305 or GY20571 Belt Part Number GY20571 Now Supersedes To GX20305 1/2 X 139" See Description Below for more information about Laser OEM replacement belts.