T2.5 are really small belts, fine for small servo controlled camera mounts, motorised telescopes and the like. If space is limited and but you want a higher rated belt, go for the 'AT' type rather than the 'T' type. You would need the matching 'AT' pulleys though as the teeth are a different profile. I have the advantage of having all the belts to hand and you get a gut feeling of what would be man enough for a job - sod the science and mathematics.