Reverse stock split. So for example. The share price is .04 and they want a dollar. They will give you 1 share for every 25 you own thus making the share price $1.00.
If you owned 10000 shares at .04 with is $400, you would then get 400 shares at $1 which is worth $400. Not a good deal, even though they are the same dollar for dollar I have seen RS happen that took a share from pennies to dollar and quickly fell to the pennies again.