the 5124 which is also used on the 5101. It probably will be a lot easier to see the former than the latter! Only a personal opinion but I think the 5124 strap looks terrible on the 5970 - tried it on mine. Clashes with all the colours of the watch but would look good on a RG or J. The 'two tone' patent leather blue 5296 strap bounces nicely off the 5970 hands and moon disc. My AD got me a number of different ones into stock for me to try - patent, plain, various alligator scales, colours. etc - a service you unlikely to get elsewhere.