Video was helpful in choosing a new cutting disc. This company has been very helpful and I highly recommend them. I had to replace my main motherboard in the past, then found out no one in the Phoenix area would reprogram it for my machine. I shipped the mower across the country to them and they serviced it promptly and discovered some other minor issues and fixed those too. The 450X now has over 30,000 miles on it and is still running in the desert heat.