Gather the parts
The Kubi ring with the old (leaking) glove still attached, alongside the replacement. DTTFF uses AlphaTec by Ansell industrial butyl rubber gloves — robust, dexterous, and a reliable choice for cold technical diving. Make sure the new glove is the right size for your Kubi ring before you start stripping the old one.
Tools you need
You need very little: a plastic o-ring pick (or a dental floss pick — the forked plastic end works perfectly), a pot of silicone o-ring grease, a clean cloth, and scissors for trimming. Avoid metal picks — they can nick the o-rings and cause the leak you were trying to fix.
Remove the red sleeve o-ring
Start at the outermost o-ring — the large red one that seals the Kubi ring to the drysuit sleeve socket. Hook the pick under the o-ring at one point and work it out of the groove carefully. Go slowly: this ring does most of the sealing work and any damage means a flooded glove underwater.
Remove the black protection-ring o-ring
Below the red o-ring sits a smaller black o-ring that holds the protective outer ring in place over the glove assembly. Use the same technique — pick it out of its groove carefully. Once it's off, the outer protective ring can be slid free, exposing the glove and inner ring beneath.
Remove the glove retaining o-ring
The innermost o-ring holds the glove itself onto the inner ring. Unlike the others, no tool is needed — simply pull firmly on the old glove and it will roll off, taking the o-ring with it. With all three o-rings removed and the old glove off, the inner ring is bare and ready to accept the new glove.
Fit the new glove to the inner ring
Push the inner ring into the new glove, making sure it seats straight. First stretch the retaining o-ring over the ring to hold the glove in place loosely, then work around the ring to centre the glove and confirm it sits evenly before seating the o-ring fully into its groove. Once seated, fold the cuff of the glove back over the ring and slide the protective outer ring over the folded cuff. Fit the black o-ring back into its groove to lock the outer ring in place.
Check the fit on your wrist
Before trimming, slide the assembly onto your wrist and check how much excess cuff material remains below the ring. You want just enough rubber to fold cleanly back over — too much and it will bunch up and affect the seal; too little and the glove won't stay put. Mark or note the cut line before removing.
Trim the excess glove material
Cut the surplus cuff down to size with sharp scissors. Some divers leave the full cuff intact — it works either way — but trimming keeps the assembly neater and slightly reduces bulk inside the sleeve. Cut straight and evenly all the way around. There is no going back once you cut, so err on the side of leaving a little more rather than less.
Clean and grease the red o-ring
Before refitting, wipe the red sleeve o-ring clean with a lint-free cloth and inspect it carefully for cuts, flat spots, or deformation — this is a good opportunity to replace it if there is any doubt. Apply a thin, even coat of silicone grease around the full circumference. Avoid over-greasing: a light film is all you need, and excess grease attracts grit.
Reassemble and test
Seat the greased red o-ring back into its groove — it should sit flush with no twisting. The assembly is now complete. Before trusting it in the water, do a dry fit test: lock the ring into the sleeve socket on your drysuit and pressurize the suit on land to check for leaks. Glove swaps are easier than they look and a great skill to have ready — if a glove fails at a remote site or on a liveaboard, you can be back in the water in under ten minutes.