The watch band fit for 26mm Garmin Fenix 5X,Fenix 5X Plus,Fenix 6X,Fenix 6X Pro,Fenix 3,Fenix 3 HR,Descent MK1,D2 Delta PX,D2 Charlie smartwatch.

Q1: How to avoid buying a strap that doesn't fit?

Before you buy, please pay attention to your watch model: (It is easy to get confused about whether there is an "S" or an "X" or an " ".)

1. The back of the watch(Fenix5x/5x plus ?Fenix 6x/6x pro ?Fenix 7x ?Fenix 3/HR?Descent MK1?D2 Delta PX?D2 Charlie)
2. The screw with(26mm)
3. Band mark(quickfit 26)
4. Watch manual, outer packaging

Q2: Why sent a hex screwdriver but the band itself needs a small Philips screwdriver?

We do provide the screwdrivers, it's used for the watch models that didn't come with a original quickfit watch band (such as fenix 3/3 HR).

So they can use it to remove the old band.

If your original watch band is a quickfit one, the screwdrivers are useless for your watch.

You could install it directly.