Buyers Products Front-Pin Square Jacks Model 0091415Buyers Products Front Pin Square Jacks Model 0091415 The Front Pin Heavy Duty Square Jack from Buyers Products features a spring return drop leg that allows easier expanding and retracting. The spring return is activated by pulling a sturdy front mounted pin to drop the leg. The Square Jack is often used in pairs, connected to each other, for the heaviest duty lifting. Ideal for RVs, construction trailers and tri axial trailers, the jack has a 10,000