ALL CAT Scales get checked every 90 days (4 times a yr) and their maintenance program is 2nd to none. As for the guarantee, it real and they back it every time. if you have questions or concerns about a CAT Scale simply call them 877 228 7225 x6 and see for yourself. Their headquarters is in Iowa and answer the phones 24 hrs a day! Can't say that about ANY other scale or scale co.