The Triumph speedometer/tachometer mounting bracket ring 97-4026 H4026 is a genuine Triumph part designed to securely hold the speedometer and tachometer in place on Triumph motorcycles. The bracket ring is specifically designed for Triumph models, ensuring a perfect fit and proper function. With the OE/OEM part numbers H4046 and 97-4046, and manufacturer part numbers H4026 and 97-4026, this mounting bracket ring is a reliable and high-quality accessory for Triumph riders.

This is correct for a number of years and models.  Go by the part number.

The speedometer/tach hole diameter is about 4" (for a 3-1/8" body diameter speedometer/tach) and the mounting hole diameter is about 1-3/16".

This is a used part in serviceable condition; not appropriate if you need perfection.  Priced accordingly.