Quick view Choose Options National Guard Products NGP 483 Interlocking Threshold, 3-1/2 x 7/8" MSRP: Was: $628.50 Now: $414.81 - $1,244.43 California Prop 65 Warning WARNING: This product can expose you to chemicals including Lead, which is known to the State of California to cause cancer. For more information, go to www.P65Warnings.ca.gov.