12 feet of “H” Webbing, Cinch adapter plate, ACB pocket adapters, D-ring and light retainer 

assemblies, doubles bolt extender, SS bolt kit and fasteners and Quick-adjust crotch strap. This upgrade kit will convert your BC to the quick adjustment harness, letting you go from a wetsuit to a drysuit without needing to adjust your belt slides.

Details on how the Cinch works from Halcyon's website:

Content located at http://halcyon.net/node/262#plate

The Halcyon Cinch Plate

The Halcyon Cinch adaptor plate is a high-quality injection molded assembly that attaches to your back plate. The plate has an accessory attachment slot on each end as well as two holes that affix the plate to your backplate. A series of slanted slots match the harness slots on the Halcyon back plate. A specially designed riser creates a slick surface that allows your webbing to slide freely when needed but to remain secure while standing up with tanks on your back.

Replacement Webbing 

Webbing on the Cinch Quick-adjust harness must be free of blemishes and indents, which can be found on used webbing from previous triglide positions. Included with Cinch Upgrade Kit.

ACB Weight Pocket Adapters 

A pair of adapters secure the ACB integrated weight pockets to the Cinch plate assembly and allow the Quick-adjust harness webbing to slide freely without affecting the position of the ACB weight pockets.

Light Retainer Assembly

The light retainer assembly consists of two pieces and enables easy adjustability of the diver’s harness while wearing a hip mounted primary light. A 2” reinforced piece of webbing with a grommet on one end attaches to the Cinch plate assembly, supporting the hip-mounted canister. This reinforced webbing provides a rigid surface to hold the light off the diver’s hip, increasing comfort and enabling harness adjustability. The light is held in place by a second component which buckles into the rigid light holder. The waist harness slides freely within this fixture, allowing a diver to loosen or tighten the harness without affecting the light position. The buckle allows the diver to easily adjust the light position or to remove the light while the harness remains secure. The light can be adjusted or removed while in or out of the water.

D-Ring Assembly

The D-ring assembly attaches to the Cinch plate and is fully adjustable, allowing the diver to select an optimal position for the D-ring. Larger divers or those using an argon bottle will appreciate the wide range of adjustment options. The D-ring assembly allows the waist strap to move freely without affecting the D-ring or attached accessories.

Stainless Steel Bolt Kit

Included in your Upgrade kit are all the necessary bolts to utilize any combination of Cinch accessories while attaching the Cinch plate assembly securely to the backplate. When purchasing an assembled Cinch BC System, note that some bolts will already be installed.

Quick Adjust Crotch Strap

The Quick-adjust crotch strap is webbed with an adjustable buckle that allows rapid resizing while eliminating any dangling webbing. Diver testing has proven the Quick-adjust buckle and strap holds securely even while used with a DPV. However, exploration DPV divers that prefer a fixed crotch strap can easily remove this buckle and bolt the crotch strap in the desired position. All other divers will take pleasure in the secure, easy adjustability of the Quick-adjust crotch strap.

Double Tank Bolt Extender

The Halcyon Cinch Quick-adjust system may be used with a single or double tank configuration. When in use with doubles, the lower part of the Cinch adapter plate features molded spacers to keep the harness webbing from being pinched by the tanks; this ensures the webbing can slide freely. In most cases the lower bolt of your double tanks will be of sufficient length to allow this slight offset. However, the Halcyon bolt extender allows divers to extend a short lower bolt where necessary. The bolt extender threads directly to the lower bolt of a double tank configuration; it uses an inset Allen key fitting so it can be easily tightened in place.