Supplied with certificate by serial numberOpen chain guard allows visual inspection and does not trap contamination.X5L Lever Hoist 1-1/8 US Ton x 10'Lift Overload Protected In addition the ultimate strength is 5 times Work Load Limit (WLL) meeting structural requirements of ASME HST-3 Appendix A, for use in marine and other applications as specified by US Department of Defense DOD.