RP-N two-way action relay are designed for making delays in blasting nets of a detonating cord while executing blasting works on surface and also in mines, which are not dangerous for gas or dust. It has 3 delay periods: 20, 35 and 50 ms. Relay shells are marked with distinctive colors to identify delay periods. The RP-N-20 relay shell with 20 ms time delay is red. The RP-N-35 relay shell with 35 ms time delay is white. The RP-N-50 relay shell with 50 ms time delay is black. The relay consists of two blasting caps with the delay, connected to each other with the plastic insert by crimping. DSH-V type detonating cord line segments of 30-50 cm length are fixed in free ends of blasting cap shells by means of crimping. The shell is made of steel with the tombac coating.

   The relay can be connected to detonating cord either by hitch or in an overlay with the help of an isolation tape or RP-N relay is shipped in a box. There are 260-300 relays in one box. Number of UN 0029 Classification code 1.1 В.