Staple up to 1,500 times without reloading. Electric stapler cartridge is easy to load so your work is not interrupted. Staple Cartridge fastens up to 25 sheets. 1,500 staples per cartridge forms 0.25" leg length staples. Two cartridges per box. Front loading cartridge for use with the Swingline 502e Desktop Cartridge Electric Stapler. Patented cartridge system includes the driver head, so with each replacement it's like getting a brand new unit.