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Cassin Twin

Version A Version B
Version A Version B


Version A

Front View Rear View Side View
Front View Rear View Side View

Technical Details

I acquired my Cassin Twin, Version A from Climb Max in 1999.

The Cassin Twin, Version A is forged from aluminum alloy and unfinished It has two V-slots, a side horn with two grooves, and a cable keeper. The front of the plate is essentially flat, but the rear has a "bump and groove" to help guide the carabiner. My Version A is 82 mm. long, 116 mm. wide, 19 mm. high, and weighs 159 g.

The front has two up-pointing arrows forged above the slots. The rear has two down-pointing arrows forged on the horn, and is printed with the Cassin logo, "HMS CARABINER," "ROPE UIAA-CE," "ø mm 8-9," "READ INSTRUCTIONS BEFORE USE," "TWIN," "ITALY," and "01-1H."


The Cassin Twin is quite different from a slotted ("Sticht") plate or belay tube, so it is important to read the instructions. While the climber is climbing, the belayer feeds rope through the device until the climber falls. At this time, the ropes will wedge into the V-slots, arresting the fall. To release the ropes, loop the tag ends over the races on the side and pull down.

When rappelling, the tag ends of the ropes are run over the races on top of the device to hold them out of the V slot. If you want to stop, drop the rope off of the races and it will lock into the V slot. Releasing it from this position requires looping the rope back over the races and pulling down hard - you may have to loop the rope around your foot and stand to do this, but usually it will just pop loose.

If you like the Twin but only need to be able to handle a single rope, the Cassin Logic might be what you are looking for.

Instructions Instructions

Version B

Front View Rear View Side View
Front View Rear View Side View

Technical Details

RiggingOlivier Peron Caillet donated a Cassin Twin, Version B to my collection in February, 2008.

Version B is similar to Version A except that Version B is anodized and has a 40 mm. long, 7.4 mm. diameter unfinished aluminum bar attached to the keeper sling. My Version B is 82 mm. long, 115 mm. wide, 18 mm. high, and weighs 159 g.

The underside of Version B is marked with the Cassin logo, "HMS KARABINER," "ROPE UIAA-CE," "ø mm 8-9," "READ INSTRUCTIONS BEFORE USE," "TWIN," "ITALY," and "01-II." There are two forged up-pointing arrows on the top side, above the rope slots, and a forged down-pointing arrow on the bottom side, below the races.


The bar helps keep the Twin from sliding on the carabiner.