This is a Peco ST-2031 HO/OO Code 100 3rd Radius Double Curves (4pcs)

PECO Setrack 00 Gauge Code 100 - Unit trackage System
The high quality rigid unit trackage system suitable for all popular brands of 00 gauge model trains.
Being fully compatible with the Code 100 PECO Streamline range, it need never be discarded as your layout develops.
The solid nickel silver rails are integrally moulded into the sleeper bases for maximum realism and strength. Turnouts are fitted with an over-centre spring for immediate use, no extra levers necessary.