The 1.5" male coupling allows you to retrofit older camera installations while using existing wall mounts. This male coupling connects any Axis pendant kit (for example, AXIS T94A01D Pendant Kit) to an older mount with a 1.5" female thread of type NPS or NPT (for example, wall mounts from other suppliers). The locking nut is included. AXIS 1.5" NPS/NPT coupler plug is suitable for indoor and outdoor use. It has been thoroughly tested in various camera installations to withstand various environmental stresses such as shock, shock and vibration, corrosion (according to NEMA 4X) and UV radiation. Material: aluminum with black anodizing. Note: The National Pipe Taper (NPT) is a US standard for tapered threads on threaded pipes and fittings. The NPS (National Pipe Straight) threads are straight (parallel). Both NPT and NPS have the same thread angle, shape and pitch (threads per inch).