These are 1/2"X12" belts correct?
Reply... better late than never. Yes it is the 1/2"X12" belts. Having said that about the 240, the same problems with the MX 400, 800, 1200, the SC 1800 and SC 6000. . They snapped at the adhesive seam of the belt after about an average 6 to 8 passes on each side. The Snap (breaking of the belt) is caused on the up stroke (left side of the sharpener). The down side (right side) no problem. Having said that and instead of returning the belts, I sharpen knives with "Those" beelts only on the down side (right) of the sharpener. It's a PITA but it works after a few trials and tribulations. Conclusion...my recommendation is if you plan to use the WSKTS Work Sharp sharpener, don't purchase the MX or SC 1/2"X12" belts from Micro Mesh. if you are going to use the left side of the sharpener. Bye the replacement belts from Work Sharp. A little pricey $1.75 ea, worth it and uncomplicated with no problems compared to MM at .59 cents ea with complications.
Aloha.
"Verify-Before You Trust."