An end effector comprising: a first jaw including a sled ; a second jaw including an anvil, the first and second jaws moveable relative to one another; and a cartridge disposed on the first jaw and having a plurality of staples , each staple of the plurality of staples including legs connected by a backspan , the sled configured to directly engage each staple of the plurality of staples to eject the plurality of staples from the cartridge as the sled is longitudinally translated through the cartridge, the cartridge defining a plurality of vertical slots and a first vertical channel passing through each vertical slot of a first line of the plurality of the vertical slots, wherein a staple of the plurality of staples is disposed in each vertical slot of the plurality of vertical slots and the sled includes a first fin extending from an upper surface of the sled and being translatable through the vertical slots to directly engage each staple disposed within the vertical slots, wherein the backspan includes a chamfered surface on at least a proximal end thereof, the chamfered surface disposed at an angle θ relative a bottom surface of the backspan and the first fin extending from the upper surface of the sled has a first angled surface disposed at a first angle (α) relative to the upper surface of the sled, the first angled surface configured to engage the chamfered surface of each staple of the plurality of staples as the sled is translated through the cartridge, wherein the first angle (α) is equal to the chamfer angle (θ) and wherein the first fin includes a second angled surface proximal of the first angled surface, the second angled surface defining a second angle (γ) with the upper surface of the sled, characterised in that the second angle (γ) is greater than the first angle (α), the second angled surface configured to engage the chamfered surface of each staple subsequent to the first angled surface engaging the chamfered surface of each staple. a first jaw including a sled ; a second jaw including an anvil, the first and second jaws moveable relative to one another; and a cartridge disposed on the first jaw and having a plurality of staples , each staple of the plurality of staples including legs connected by a backspan , the sled configured to directly engage each staple of the plurality of staples to eject the plurality of staples from the cartridge as the sled is longitudinally translated through the cartridge, the cartridge defining a plurality of vertical slots and a first vertical channel passing through each vertical slot of a first line of the plurality of the vertical slots, is disposed in each vertical slot of the plurality of vertical slots and the sled includes a first fin extending from an upper surface of the sled and being translatable through the vertical slots to directly engage each staple disposed within the vertical slots, wherein the backspan includes a chamfered surface on at least a proximal end thereof, the chamfered surface disposed at an angle θ relative a bottom surface of the backspan and the first fin extending from the upper surface of the sled has a first angled surface disposed at a first angle (α) relative to the upper surface of the sled, the first angled surface configured to engage the chamfered surface of each staple of the plurality of staples as the sled is translated through the cartridge, wherein the first angle (α) is equal to the chamfer angle (θ) and wherein the first fin includes a second angled surface proximal of the first angled surface, the second angled surface defining a second angle (γ) with the upper surface of the sled, characterised in that the second angle (γ) is greater than the first angle (α), the second angled surface configured to engage the chamfered surface of each staple subsequent to the first angled surface engaging the chamfered surface of each staple. <EOS>