The opening of each slotted jack pad is 0.378", depth is 0.642", wide by 2.992" in length;.
Large Slotted Universal Magnetic Jack Pad Pinch Weld Rail Adapter Aluminum
Red Slotted Universal Magnetic Jack Pad Pinch Weld Frame Rail Adapter (PAIR)
Premium Slotted Universal Magnetic Jack Pad Pinch Weld Frame Rail Adapter Red
Jack Pad Slotted Universal Magnetic Frame Rail Protector Protector Puck/pad50 Mm