ISOfrane Poseidon Yellow Rubber Watch Strap

Earn up to 695 Holben’s Rewards points on this purchase
Size (lug/buckle):
  • Made in Italy.
  • Swiss company ISOfrane introduced this timeless dive strap in the early 1960s.
  • Due to its innovative design and material, ISOfrane became the strap of choice for some of the most iconic dive watch makers of the 1960s and 1970s.
  • Reintroduced by Synchron in 2010, with an improved proprietary isoprene rubber compound for even better durability and softness.
  • 100% silicone-free.
  • Will not attract lint and dust like silicone.
  • Waterproof, hypoallergenic and nontoxic.
  • Large slots for ventilation and water drainage.
  • Ribbed underside prevents strap from sticking to the skin.
  • Thirteen sizing holes to achieve the perfect fit.
  • Piece length 130mm / 75mm excluding buckle.
  • Total length approximately 8" excluding buckle.
  • Thickness tapers from 5.5mm at lug ends to 3.5mm at opposite ends.
  • Vanilla scent.
  • Available with ISOfrane's Retrosicuro buckle in either brushed stainless steel or black DLC (diamond-like carbon) finish.
  • Includes one free pair of strong, seamless double-flange stainless steel spring bars.

Q: Do you sell watch bands for women?
A: We do! Many of our short-length straps are the perfect size for women.

Q: Can you suggest a strap that looks amazing with my watch?
A: Unfortunately, because the range is so vast (and personal taste is subjective), we cannot advise regarding aesthetic suitability for specific models and styles of watches.

Q: I have an Apple watch. Will any of your straps work for me?
A: Sure! Our handy Apple watch band adapters accommodate most 22mm straps.

Q: Are spring bars available?
A: Yes, for each strap that is not already integrated with quick-release spring bars, we include one free pair of strong, seamless double-flange stainless steel bars.

Q: What strap size do I need?
A: To determine your size, use a metric ruler to measure the internal distance (in millimeters) between the lugs of your watch.

Q: My Bonetto Cinturini deployant strap is too long. Can you help?
A: Of course! See our Bonetto Cinturini sizing guide for cutting instructions.

Q: Do you offer international shipping?
A: Yes! Visit our Shipping & Returns page for more information.

Q: May I return my purchase?
A: Holben's Fine Watch Bands accepts returns of unworn, undamaged merchandise for refund or exchange within thirty days of purchase. Learn more on our Shipping & Returns page.

Need help with sizing?
  • Inspect the underside of your current watch strap for width indicators.
  • Measure the space between your watch lugs (in millimeters) using a metric ruler.
  • Research the specifications of your watch model on the manufacturer's website.
Shopping for your Apple watch?

Our stainless steel adapters enable the use of virtually any 22mm watch band with Apple Watch models 1-8, SE and Ultra, and are compatible with standard or quick-release spring bars.

Shipping & Returns

Not to brag, but Holben's is famous for our fast shipping!

United States deliveries:

All domestic shipping options include tracking.

FREE USPS Ground Advantage shipping (3-5 business day transit time) for orders over $39.
$4.95 USPS Ground Advantage shipping for orders up to $39.00.
$8.95 USPS Priority Mail (2-4 business day transit time).
$23.95 USPS Priority Mail Express (1-2 business day transit time).

International deliveries:

Quickly-dispatched USPS First Class International shipping for one flat fee of $16.95, regardless of number of items purchased.

Orders shipped outside of the USA may be subject to customs or import fees upon arrival in the destination country. Payment of any import duties, fees or taxes is the responsibility of the customer. Contact your local customs office for information regarding potential charges.

Returns & Exchanges

Holben's accepts returns of unworn, undamaged watch straps or accessories for refund or exchange within thirty days of purchase. (To ensure that items remain in original condition, please confirm suitability before fastening to your watch or wrist.)

All product packaging (bags, tags, cases, etc.) must be unaltered and returned with each item. Items without original packaging will be refused. Items that have been worn, resized, damaged or otherwise modified (including exposure to cologne, tobacco smoke, household air fresheners or other odors) will not be accepted.

Orders must be packed in a padded envelope or small box, and shipped via USPS with delivery confirmation. (Couriers such as DHL and UPS will not deliver to PO boxes.)


Please ship all returns to the address below, with a note stating your name, date of purchase and reason for return.

Returns Department
PO Box 10853
Bainbridge Island, WA 98110

We are happy to help with returns and exchanges. If you have any questions, please contact us.

Customer Reviews

Based on 4 reviews
Shane Watson
Best band made!

Immediately fell in love with this band the second it was installed, It doesn’t even feel like I’m wearing a watch with this band

Classic and very well made

Every reviewer I checked out seemed to feel that this strap was top notch. I fully agree.

Heavy duty

Amazing strap for comfort on hot summer days. Made of thick rubber. I don’t really notice the “vanilla smell” some people are talking about. Only thing I’d change would be the length of the strap. It’s almost too long even on my 7.5” wrist. Oh and the price is pretty steep but you get what you pay for. Like usual, the strap shipped very fast.

Donny Lovelace
Rugged and Beautiful Leather Strap

I was looking for a new strap to replace the one that came with my Citizen Promaster Dive watch and cannot be any happier with the Isofrane in anthracite that I chose. It is a high quality rubber strap that perfectly complements the watch. A very rugged look that matches the tool watch aesthetics of the watch, while also being high quality. I’m sure this strap, like the watch, will serve me well for many years. Purchase from Holben’s was fast and easy. Despite being shipped across the country, I received the strap quickly. First time customer, but it won’t be my last purchase!

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