The product below was linked in first by John @AweEnthusiast
TECHNICAL SPECIFICATIONS
SIZE 26 32 38 Surface area (m2) 26.07 31.62 38.08 Line length (m) 5.26 5.79 6.35 Centre line (m) 5.34 5.88 6.45 Weight (kg) 1.3 1.5 1.7 Packed volume (cm3) 4100 4600 5100 Sink rate (m/s) 5.0 4.8 4.8 Maximum load (kg) 86 104 126 Certification EN EN EN
By my fast calculation, this leads to huge drag coefficients (air density 1.2): 2.2 for the 26, 2.38 for the 32, and 2.39 for the 38.