Stens Shield 770-031 32 oz SAE 30 4-Cycle Engine Oil - 12 per Case - As a leader in aftermarket replacement parts, Stens provides parts to the outdoor power equipment, industrial/rental, hardware, turf management, golf course, and agricultural equipment markets. Stens, headquartered in Jasper, Indiana, joined Arrowhead Engineered Products, based in Blaine, Minnesota, in December 2016. This merger combined two of the strongest aftermarket parts suppliers in the industry.