Change any watch strap you like to fit your new Apple Watch with our Full Set ( Custom Made Vintage Strap + Already Installed Adapter with Steel/Alu or Space Gray Color + Stainless Steel Brushed buckle + 5 Edges Screw Driver for Strap Change later ) 
What you have to do is: Remove the old strap, slide in the new vintage custom made strap from us – finish!
Please visit my shop for many strap designs.
If you do not notice the strap size, we will make a 125mm/75mm strap for you which will fit almost all normal wrist => please leave us a message if you have bigger or smaller wrist (base on the wrist chart). We will personalize the strap to fit your wrist- no worry. Moreover, you can also custom the leather type, stitching color
Please notice also you are using Alu/Steel Color or Space Gray Color Watch sothat we can install the right color adapter to match your Apple Watch, If not we will deliver the Steel Color which match the Alu/Steel Color Apple Watch Version
Wrist chart (4-6,5mm thick for 44mm, 47mm, 52mm case)
(in cm- in inches- Short/long strap)
12,7cm-14cm = 5.0″-5.5″ = 65mm/115mm.
14cm-15,2cm=5.5″-6.0″ = 70mm/120mm.
15,2cm-16,5cm=-6.0″-6.5″ = 75mm/120mm.
16,5cm-17,8cm= 6.5″-7.0″ = 75mm/125mm.
17,8cm-19,05cm=7.0″-7.5″ = 80mm/130mm.
19,05cm-20,32cm=7.5″-8.0″ = 80mm/135mm.
20,03cm-21,59cm=8.0″-8.5″ = 85mm/140mm.
21,59cm-22,86cm=8.6 – 9.0″ = 85mm/145mm.
22,86cm-24,13cm=9.0 – 9.5″ = 90mm/150mm.
24.14cm-25.4cm=9.0 – 9.5″ = 90mm/155mm.

Notice: 
*) buckle is included; with a pair/2pcs Adapters (Steel or Space Gray Color) of 42mm or 38mm + 1 Screw driver => we will built in a set for you What you have to do is: Remove the old strap, slide in the new vintage custom made strap from us
NOTICE
*) We recommend: 
for AW 42mm lug : should combine with 24mm/22mm strap
for AW 38mm lug : should combine with 22mm/20mm strap

Please feel free to contact me if you have any further questions or concerns.