Poly Technologies Paratrooper 8-3/4in Stainless Steel SKS Gas Piston Stainless. Some SKS Para trooper rifles take a standard SKS gas piston while others take a shorter one. The shorter 8 3/4'' gas pistons are very hard to find. This fits the Para Trooper SKS with the shorter 9 Inch tubes. Specifications for Poly Technologies Paratrooper 8-3/4in Stainless Steel SKS Gas Piston: Manufacturer: Poly Technologies Color: Stainless Gun Make: Kalashnikov Gun Model: SKS Package Contents: Poly Technologies Paratrooper 8-3/4in Stainless Steel SKS Gas Piston Poly Technologies 60CD4: Paratrooper 8-3/4in Stainless Steel SKS Gas Piston Stainless