1/2 inch wide strap with a Contax release lug. 

The second lug is different, so I'm not sure it's also for Contax.  Look closely before bidding if that is important to you.  The strap is 18" long when straightened out, and has fanned out to about 1 inch wide at one end. I suspect that is a flaw, not a design feature.

I don't remember the original use, but it looks like it could be a replacement strap for the leather hand grip that can be used with the battery grip MP-1.  I have a pair of MP-1s, so I might have picked up this strap and lug as a spare. 
 
I have additional Contax 645 cameras, lenses, inserts, backs and accessories for sale in other listings.

Functional condition:  Good.

Cosmetic condition:  Very good.

Guarantee:  Item is guaranteed to be exactly as described and fully functional.  For local pickup:  if you complete the purchase here on eBay and then find an issue that I did not mention in this listing when you come to pick up the printer, I will go online, cancel your purchase and issue a full refund while you are here.

Shipping:   I try to offer multiple shipping options.  Since I don't know which option will be the fastest and / or the least expensive to your postal code, please check out all available options before picking one.  I offer combined shipping for multiple purchases paid for at the same time.  Where possible I will ship everything in one box and pass all shipping cost saving along to the buyer.  Request a custom combined invoice before paying if this applies to you

Returns:
  • NO RETURNS for cosmetic issues, as the photos in this listing are extensive, are of the exact item for sale in this listing, and were taken recently.
  • I will accept returns for functional issues not mentioned in the listing.  To keep us both honest, I will refund the original shipping charges in full, but the buyer will pay the return shipping cost. 
Feedback:  Even a quick look through my feedback from buyers makes it clear that I am honest and accurate with my descriptions.  I will leave feedback for all buyers, and ask that all buyers leave feedback for me.  I strive for 5-star detailed feedback in all categories.  If you don't honestly feel that I've earned 5-star feedback, let me know the problem.  I'll try, if possible, to make things right.