The Kinesis "Heavy-duty Belt" --
Commonly used with packs or for those carrying several
F2.8 zooms and an SLR on their waist.

Belt Sizing Info

Home > B-Series > B307, B308, B309 & B311
All belts include a pair of B501 sliders.

From the top: B307, B308 & B309 (B311 not shown).

[B307] Medium Heavy-duty Belt, $56.00

Optimum fit for 29-33" (72-84cm) waist. Fits up to 46" (117cm).
Seven attachment points. Space for six single-wide pouches, three double-wide pouches or equivalent.

[B308] Large Medium Heavy-duty Belt, $56.00

Optimum fit for 34-38" (85-97cm) waist. Fits up to 50" (127cm).
Eight attachment points. Space for seven single-wide pouches or equivalent.

[B309] X-Large Medium Heavy-duty Belt, $56.00

Optimum fit for 39-47" (98-120cm) waist. Fits up to 54" (137cm).
Nine attachment points. Space for eight single-wide pouches, four double-wide pouches or equivalent.

[B311] XX-Large Medium Heavy-duty Belt, $66.00

Optimum fit for 48-54" (121-137cm) waist. Fits up to 64" (162cm).
Eleven attachment points, or space for ten single-wide pouches or equivalent.

The Heavy-duty belt is wider than the Black Belt. it is 11cm wide (4.25"). It provides more support for the heavier loads. It is also over three times as thick as the Black Belts. Read here for a comparison discussion.

Weight of B308 = 11 oz. (312 g)

Heavy-duty belts are made from bi-laminate foam for a more comfort with heavy loads.