It seems they've changed the names again; there's no TR anymore just an SL.
https://www.tartybikes.co.uk/complete_freewheels/echo_sl_108_screw_on/c16p10864.html?pos=1205&search_params=YTo3OntzOjEyOiJjYXRlZ29yeV9pZHMiO2E6MTp7aTowO3M6MjoiMTYiO31zOjE2OiJjYXRlZ29yeV9yZWN1cnNlIjtiOjE7czo4OiJrZXl3b3JkcyI7czowOiIiO3M6OToiYnJhbmRfaWRzIjtOO3M6NDoibW9kZSI7czozOiJhbGwiO3M6NDoic29ydCI7czo5OiJwcmljZV9hc2MiO3M6MTA6ImNvdW50cnlfaWQiO3M6MToiMSI7fQ%3D%3D
You can also get a titanium version too, but they've been known to be weaker.