Royal marines stuff? i know nothing about half of the stuff i picked up

I was walking about stroud (im on holiday too Gloucestershire) and came across a webbing being given away for free and obviously i took it because what army soldier wanna be wouldnt, once i took it back too the house im staying at and everything i found was quite interesting, i found a 5.56 round, a HARRIS MIL 2800 TRANSCEIVER HANDHELD, two tone hand and face paint with insect repellent included, two badges (one saying RM and the other has a golden soldier marching with his weapon in front of a red background), a net/rope sort of thing, a black water bottle without the cup bit, a belt with bullet holders, and a really old torch with a clip (it still works), the walkie talkie came with a cover and an antenna too

on the back pocket very faintly marked it says 'big brain'