The timing belt sprocket (gear) fitted to the nose of the crankshaft can more often than not be quite tight to remove by hand. It is supposed to be a sliding fit, but over time and with some corrosion, they tend to get stuck.
We designed this tool years ago and have been using it in the workshop, and all you need is a balancer puller to hook onto it.
Made in Australia using 6061 Billet.
Fits all Nissan RB engines (20/25/26/30)