For those who prefer a Webber style stirrup strap, Ghost has designed a T-bar stirrup strap. The top has a nylon loop that goes through the stirrup ring and there's a leather cover for the T-bar.
The hole in your stirrup needs to be 30mm x 10mm (1.25" x 0.25") minimum for the T-bar to fit through. Not recommended for jumping or hard use.
Note: due to a worldwide shortage in T-bars, the design will be changing from the T-bar to a Conway. I have some T-bars still in stock (not short ones) and will be getting the Conway version in stock soon.