BRM

The weaver is the same basic configuration as a dovetail in that there are 2 outside clamps onto a mount. However with the weaver the tightening screw has a square section which fits between the slots and so only allows the mount to be fitted in this location. This stops scope creep and also (in theory) allows scope removal and replacement without losing zero, especially useful if swapping NV and Day scopes.

I don't have dims to hand, sorry