Metal Slide, Polymer Lower. Full Trades. Unsure of brand as no markings ? Isn’t blowing back fully on each shot. Shoots the BB ok but slide only goes back partially so doesn’t load next shot/reset hammer. If you rack it manually each time it shoots a BB each time. My guess is a worn seal/o ring in the blowback unit ? Or possibly light striking from a worn hammer spring ? I’m only guessing tho. Came to me with other boneyard parts but selling as my interest is with my other Glocks. 
 

I would consider a swap for anything Glock Boneyard as have plenty of spares to play with. 
 

postage is £5 if buying and buyer to cover PayPal fees.... cheers