A shopping challenge - Kitchen type timer with hours please?

[What2donow4]

I'm looking for a timer to remind an elderly relative to go to the bathroom when I'm out at work. She can't cope with phone timers, etc. so I was thinking of a kitchen timer like
amazon.co.uk/Salter-Big-Button-Timer-Electronic/dp/B002BT0BD4/ref=sr_1_9?ie=UTF8&qid=1534494181&sr=8-9&keywords=kitchen+timer THIS]]
as she can hear it and understands how to operate the start and stop buttons. However my kitchen one and all those I can find only go up to 99 minutes, and as we are bladder training we need one that does three and four hours. It does need to be pretty loud and we need to get hold of it speedily!

Has anyone seen anything suitable please?

www.amazon.co.uk/TopElek-Countdown-Function-Retractable-Magnetic/dp/B01ECDON12/ref=mp_s_a_1_3?ref=plSrch&keywords=hour+timer&dpPl=1&dpID=51GyMMU3s0L&pi=AC_SX236_SY340_FMwebp_QL65&tag=mumsnetforum-21&ie=UTF8&qid=1534494566&sr=8-3

Perfect, thank you so much. Getting her back to independence seems a constant problem solving activity that I'm finding more challenging than my children!

You're very welcome, I hope it works okay! I'm sure she appreciates all that you're doing for her.