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International Safety Components (ISC) A•B


Front View Rear View
Front View Rear View
Side View Front View: Open for Rigging
Side View Front View: Open for Rigging

Technical Details

I acquired my ISC A•B from Jon Edelman in 2015.

My ISC A•B is 206 mm. tall, 65 mm. wide, 35 mm. thick, and weighs 454 g. The front and rear plates and the handle plate are stamped from 3.9 mm. aluminum, cut and formed to shape, and anodized. The top portion of the plates are 19.6 mm. apart, but the lower portions bend until they nearly touch, which they may under load. The rear plate has 14 mm. wide by 29 mm. high irregular eye. There is a 12.6 mm. diameter pin fixed near the top of the rear side plate, and it forms the axle for the pivoting side plate. A second, 10.9 mm. pin attached to the rear plate (35 mm. below the first pin) supports the control lever and the lower bollard. The pins are pressed into conical bushings on the outsides of the plates, then riveted to secure them in recesses cut into the bushings.

The pivoting side plate has a spring-loaded, stamped, steel gate that allows one to rig the bobbin without unclipping from the seat harness.

The lower bollard is a 42 mm. diameter, 15 mm. thick aluminum disk with a 24 mm. long flat surface on the bottom and a 2.1 mm. deep U-shaped groove around the remainder of its perimeter. It pivots on the lower pin, with the pivot axis offset 12.5 mm. from the disc’s center.

The handle pivots on the same post as the lower bollard, fitting between the bollard and the rear plate. The handle has a spring-loaded extension that the user can unfold to provide extra leverage. Friction from the main rope’s passage tends to turn the lower bollard towards the upper pin until the handle contact the upper bollard.

The upper end of the handle plate has an 15.9 mm. diameter, 14.7 mm. long post riveted into it.The post has a 1.8 mm. deep U-shaped groove. The outer end of the post has a 21.5 mm. flange. With the handle in the lowest position, the gap between the post and the upper bollard is 6.5 mm. A strong, hidden wire spring acts to close the handle.

The front of the device is printed with "I|S|C," "A•B," "DESCENDER," "Made in UK," "EN12841-C," "Ø 10.5-12.5 MAX 300kg," "EN341-B," "20x100Mx100kg," " ROPE," a book-with-an-"i" icon, "CE-0120," a diagram showing how to rig the A•B, and "12/26550/04."


The A•B is essentially the same device as the SAR SB.

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