Thanks for your reply Steve,
He has been bench pressing now for 4 years and is in his late 50’s. The shirt is a Titan brand and although Im not sure on the exact sizing it takes a bit of work to get it on.
Over the last 6 weeks I have tried to get hime in the shirt at least once per week, as he has a competition in mid October. With other days focusing on max effort assistance exercise-( floor press, rack lock outs, decline press) and power/speed bench, incorporating throws and band work.
Each day has had further assistance exercises ( back, shoulder, arm work etc) normally following a 3 week cycle from 10-15 reps, to 6-8 reps. I have started to phase out some of the assistance work as he gets closer to competition.
Really wanting to maximise the next 6 weeks before competition in October.