The opening of each slotted jack pad is 0.378", depth is 0.642", wide by 2.992" in length.
Universal Magnetic Jack Pad, 0.37" Slotted Aluminum Grooved Jack Puck Pinch, Pin
Red Slotted Universal Magnetic Jack Pad Pinch Weld Frame Rail Adapter (PAIR)
Premium Slotted Universal Magnetic Jack Pad Pinch Weld Frame Rail Adapter Red
2X Universal Magnetic Jack Pad Pinch Weld Frame Rail Adapter Aluminum