If you climb regularly – whether at the gym or on real rock – you know what a flapper is.

It's that painful moment when a callus on your palm tears open mid-crimp.

Not fun.

This callus care sanding block is designed specifically to prevent that from happening by keeping your calluses smooth and even, so they don't catch and tear.

The block is cylindrical (about 1 inch in diameter) with two grooves that give you a natural, secure grip – your thumb sits in one, your fingers in the other.

It's easy to hold and control, even with sweaty or chalky hands.

The sandpaper grit is optimized specifically for palm calluses – not too coarse to damage healthy skin, but rough enough to smooth down raised calluses.

It's been tested and selected to do the job without over-sanding.

The body is made from hard maple wood, which is smooth and durable, and it's got a nice natural feel that gets even better with use.

Plus, there's a bit of charm in using a wooden tool for hand care.

You also get one extra piece of sandpaper so you can replace it when the first one wears out, and a handy rope and pocket are included – the rope lets you hang it on your bag, and the pocket keeps the sandpaper from scratching up the inside of your pack.

This is a small, simple tool that makes a huge difference for climbers.