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. Staple Collation: Cartridge; Staples per Strip/Cartridge: 1,500; Sheet Capacity: 25; Leg Length: 0.25".