The TR150 10-digit pocket calculator fits in my shirt pocket and I bought it to keep with my reusable shopping bags now that supermarkets no longer offer plastic bags. It also has a separate back plate to protect it when not in use.
I went to Staples to buy a few replacement SPL 110 and SPL 130 calculators to go in my Aluminum invoice boxes for work But they were not available or no longer stocked and this was the closest in size and shape. When I buy items that work well and provide for my needs I am sad when they are discontinued. It often seems like planned obsolesence!
You have to hit keys hard and they are so big that it's easy to make a mistake. Plus the + key is not flat purposely made with an angle makes no sense. Not recommended if you use often to add many items.