The only potent thing that i've found for 100lbs and more are :
Elite Set 5-130 $848/pair ($99 S/H) Our most popular Pro Handle in a 130 lb Set!
http://www.powerblock.com/blocks.html
The Elite Set 5-130 x 5 lbs set comes with plates 1-11, and adjusts in 5 or 10 lb increments. The Elite Set 5-130 lb (per hand weight) equals/replaces 37 pairs of dumbbells, or 4820 lbs of free weights while taking up the space of just 1 pair.
AND
http://www.ironmaster.com
The Quick-Lock Dumbell Add on Kit adds 45 lbs to each dumbell to bring them up to 120 lbs each. Our new style kit makes adding extra weight even quicker and includes 4ea. longer locking screws and 4ea. 22.5 lb weight plates. You can put the "big" plates on the handles first or add them on top of the original plates. Very simple to use. The longer locking screws allow dumbell sizes of 70-120lbs. The standard Quick-Lock dumbell rack will hold the full 120 lb dumbells.
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165 lb Add on Kit - Custom
This is a custom built add on weight kit for the Quick-Lock Dumbbells to bring them up to 165 lbs. It is only available as a special request and they are built to order. The extra long locking screws are fully threaded wich require them to be screwed in and out all the way to make a weight change. This is to add extra strength and safety in the upper weight range. Please expect a little extra time required to make a weight change.
It should be noted that the Quick-Lock Dumbbell handles are not designed for use above 120lbs. The use of this custom add on kit may void the lifetime warranty of the original product if they are dropped or abused. Custom products are not returnable. We have built many of these custom add on kits and they work really well and lock up nice and tight. Fully loaded dumbbell is 23.5" long.
Please contact us to place a custom order request. We build them to order so please allow 2-3 weeks. Price is $235.00 plus $45.00 shipping.