There are two variants of the TS Photoline 130/910 FPL53 Triplet, one with 2.5 inch and one with 3.7 inch focuser. They are listed as separate products on the TS website, have different capability (2.5" focuser can carry equipment payload of 5kg, 3.7" focuser has payload of 8kg), have significantly different prices, and are different weights.