What is Reddit's opinion of Champro Reaction Ball?

From 3.5 billion Reddit comments

Just piggy backing on what everyone else is saying. Staying on the balls of your feet help you be more springy. My recommendation is focus on footwork with no digging. Try using a reaction ball. Helps you stay active and move to your target. Once you get comfortable with your footwork, then proceed with digging.

this will help you train to be faster

https://www.amazon.com/Champro-CBBRB-Reaction-Ball/dp/B002N4R56S

and so will ping pong / table tennis

after that it is just hours of muscle memory to recognize how hard someone hit at you and to get your platform set quick and straight

Lots of good suggestions so far. I'll add some cheaper items in case you want to put some things in a tennis bag or simple gift bag:

Reaction Ball

Tourna Grip Enhancer for sweaty hands

Tourna Rosin Bottle

Winning Ugly

The Inner Game of Tennis

Of the two books, I guess for a high schooler I would choose Winning Ugly. Of the two items for sweaty hands, I use the Tourna Rx and like it but I think that the two are really the same thing. The second is rosin in powder form. The first might be rosin in solution. The solution evaporates as you rub it on your hands. The reaction ball helps your hand eye coordination and foot work.

Hope your brother loves whatever you get for him.

There are a ton of dog bouncy balls designed to bounce irregularly. They are hard and designed for a dog to chew on. There are also versions designed to throw at a wall or on the ground so you can react quickly. Good for sport training I guess. These ones are called React Balls.

https://www.amazon.com/CHAMPRO-CBBRB-Champro-Reaction-Ball/dp/B002N4R56S

There is a waboba moon ball which isn't exactly an octagon but it has flat-ish sides: https://www.amazon.com/Waboba-Moon-Ball-Colors-Vary/dp/B07L4K66LG

Do these help at all?

It kinda looks like this

Yes but more reaction ball shaped. Kinda like the older diagrams of neutrons

https://www.amazon.com/dp/B002N4R56S/ref=cm_sw_r_cp_api_i_LINPDbHBQR6JX

Kinda like that but I think it had a central sphere with three more attached to it.