Yes, the No4 version of the SMLE.
SMLE stands for Short Magazine Lee Enfield, they started making them in 1907.
If you have a SMLE take a look at your fired brass, they actually bulge about 1/4in down from the rim, the chambers on these rifles are oversized. This way if you has dinged up ammunition or ammunition with crappy tolerances they could still be fired. This is one of the reasons the Ross was never reliable, the Canadian ammunition was very good and the british was not, therefore the poor british ammo caused failures in the ross rifles, that and mud.
So, SKS mags, yes they need to be pinned to 5rds but the SKS-D does allow you to use detachable mags. Another option is to get standard stripper clips that are 10 rounds and cut them down to have 5 round stripper clips, this is assuming you are not mounting a scope.